IMPORTANCE OF RESEARCH AND SCIENTIFIC METHODS
TO UNDERSTANDING NUTRITION
1.2: Introduction
Learning Objectives
What are Nutrients?
The foods we eat contain nutrients. Nutrients are substances required by the body to perform
its basic functions. Nutrients must be obtained from our diet, since the human body does not
synthesize or produce them. Nutrients have one or more of three basic functions: they provide
energy, contribute to body structure, and/or regulate chemical processes in the body. These
basic functions allow us to detect and respond to environmental surroundings, move, excrete
wastes, respire (breathe), grow, and reproduce. There are six classes of nutrients required for
the body to function and maintain overall health. These are carbohydrates, lipids, proteins,
water, vitamins, and minerals. Foods also contain non-nutrients that may be harmful (such as
natural toxins common in plant foods and additives like some dyes and preservatives) or
beneficial (such as antioxidants).
Macronutrients
Nutrients that are needed in large amounts are called macronutrients. There are three classes
of macronutrients: carbohydrates, lipids, and proteins. These can be metabolically processed
into cellular energy. The energy from macronutrients comes from their chemical bonds. This
chemical energy is converted into cellular energy that is then utilized to perform work, allowing
our bodies to conduct their basic functions. A unit of measurement of food energy is the calorie.
On nutrition food labels the amount given for “calories” is actually equivalent to each calorie
multiplied by one thousand. A kilocalorie (one thousand calories, denoted with a small “c”) is
synonymous with the “Calorie” (with a capital “C”) on nutrition food labels. Water is also a
macronutrient in the sense that you require a large amount of it, but unlike the other
macronutrients, it does not yield calories.
Carbohydrates
Carbohydrates are molecules composed of carbon, hydrogen, and oxygen. The major food
sources of carbohydrates are grains, milk, fruits, and starchy vegetables, like potatoes. Non-
starchy vegetables also contain carbohydrates, but in lesser quantities. Carbohydrates are
broadly classified into two forms based on their chemical structure: simple carbohydrates, often
called simple sugars; and complex carbohydrates.
1.2.1 49290 Simple carbohydrates consist of one or two basic units. Examples of simple
sugars include sucrose, the type of sugar you would have in a bowl on the breakfast table, and
glucose, the type of sugar that circulates in your blood.
Complex carbohydrates are long chains of simple sugars that can be unbranched or branched.
During digestion, the body breaks down digestible complex carbohydrates to simple sugars,
mostly glucose. Glucose is then transported to all our cells where it is stored, used to make
energy, or used to build macromolecules. Fiber is also a complex carbohydrate, but it cannot be
broken down by digestive enzymes in the human intestine. As a result, it passes through the
digestive tract undigested unless the bacteria that inhabit the colon or large intestine break it
down.
One gram of digestible carbohydrates yields four kilocalories of energy for the cells in the body
to perform work. In addition to providing energy and serving as building blocks for bigger
macromolecules, carbohydrates are essential for proper functioning of the nervous system,
heart, and kidneys. As mentioned, glucose can be stored in the body for future use. In humans,
the storage molecule of carbohydrates is called glycogen, and in plants, it is known as starch.
Glycogen and starch are complex carbohydrates.
Lipids
Lipids are also a family of molecules composed of carbon, hydrogen, and oxygen, but unlike
carbohydrates, they are insoluble in water. Lipids are found predominantly in butter, oils,
meats, dairy products, nuts, and seeds, and in many processed foods. The three main types of
lipids are triglycerides (triacylglycerols), phospholipids, and sterols. The main job of lipids is to
provide or store energy. Lipids provide more energy per gram than carbohydrates (nine
kilocalories per gram of lipids versus four kilocalories per gram of carbohydrates). In addition to
energy storage, lipids serve as a major component of cell membranes, surround and protect
organs (in fat-storing tissues), provide insulation to aid in temperature regulation, and regulate
many other functions in the body.
Proteins
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Personal Choice: The Challenge of Choosing Foods
There are other factors besides environment and lifestyle that influence the foods you choose to
eat. Different foods affect energy level, mood, how much is eaten, how long before you eat
again, and if cravings are satisfied. We have talked about some of the physical effects of food
on your body, but there are other effects too.
Food regulates your appetite and how you feel. Multiple studies have demonstrated that some
high fiber foods and high-protein foods decrease appetite by slowing the digestive process and
prolonging the feeling of being full or satiety. The effects of individual foods and nutrients on
mood are not backed by consistent scientific evidence, but in general, most studies support that
healthier diets are associated with a decrease in depression and improved well-being. To date,
science has not been able to track the exact path in the brain that occurs in response to eating
a particular food, but it is quite clear that foods, in general, stimulate emotional responses in
people. Food also has psychological, cultural, and religious significance, so your personal
choices of food affect your mind, as well as your body. The social implications of food have a
great deal to do with what people eat, as well as how and when. Special events in individual
lives—from birthdays to funerals—are commemorated with equally special foods. Being aware
of these forces can help people make healthier food choices—and still honor the traditions and
ties they hold dear.
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Proteins are macromolecules composed of chains of subunits called amino acids. Amino acids
are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of
proteins include meats, dairy products, seafood, and a variety of different plant-based foods,
most notably soy. The word protein comes from a Greek word meaning “of primary
importance,” which is an apt description of these macronutrients; they are also known
colloquially as the “workhorses” of life. Proteins provide four kilocalories of energy per gram;
however providing energy is not protein’s most important function. Proteins provide structure to
bones, muscles and skin, and play a role in conducting most of the chemical reactions that take
place in the body. Scientists estimate that greater than one-hundred thousand different proteins
exist within the human body. The genetic codes in DNA are basically protein recipes that
determine the order in which 20 different amino acids are bound together to make thousands of
specific proteins.
Figure 1.1 The Macronutrients: Carbohydrates, Lipids, Protein, and Water. Figure 1.1 The
Macronutrients: Carbohydrates, Lipids, Protein, and Water
Water
There is one other nutrient that we must have in large quantities: water. Water does not
contain carbon, but is composed of two hydrogens and one oxygen per molecule of water. More
than 60 percent of your total body weight is water. Without it, nothing
1.2.2 49290 could be transported in or out of the body, chemical reactions would not occur,
organs would not be cushioned, and body temperature would fluctuate widely. On average, an
adult consumes just over two liters of water per day from food and drink combined. Since water
is so critical for life’s basic processes, the amount of water input and output is supremely
important, a topic we will explore in detail in Chapter 4.
Micronutrients
Micronutrients are nutrients required by the body in lesser amounts, but are still essential for
carrying out bodily functions. Micronutrients include all the essential minerals and vitamins.
There are sixteen essential minerals and thirteen vitamins (See Table 1.1 and Table 1.2 for a
complete list and their major functions). In contrast to carbohydrates, lipids, and proteins,
micronutrients are not sources of energy (calories), but they assist in the process as cofactors
or components of enzymes (i.e., coenzymes). Enzymes are proteins that catalyze chemical
reactions in the body and are involved in all aspects of body functions from producing energy,
to digesting nutrients, to building macromolecules. Micronutrients play many essential roles in
the body.
Table 1.1 Minerals and Their Major Functions Minerals Major Functions
Macro Sodium Fluid balance, nerve transmission,
muscle contraction Chloride Fluid balance, stomach acid production
Potassium Fluid balance, nerve transmission, muscle contraction Calcium
Bone and teeth health maintenance, nerve transmission, muscle contraction,
blood clotting Phosphorus Bone and teeth health maintenance,
acid-base balance Magnesium Protein production, nerve transmission, muscle
contraction Sulfur Protein production Trace Iron
Carries oxygen, assists in energy production Zinc Protein and DNA production,
wound healing, growth, immune system function Iodine
Thyroid hormone production, growth, metabolism Selenium Antioxidant
Copper Coenzyme, iron metabolism Manganese Coenzyme
Fluoride Bone and teeth health maintenance, tooth decay prevention
Chromium Assists insulin in glucose metabolism Molybdenum
Coenzyme
Minerals
Minerals are solid inorganic substances that form crystals and are classified depending on how
much of them we need. Trace minerals, such as molybdenum, selenium, zinc, iron, and iodine,
are only required in a few milligrams or less. Macrominerals, such as calcium, magnesium,
potassium, sodium, and phosphorus, are required in hundreds of milligrams. Many minerals are
critical for enzyme function, others are used to maintain fluid balance, build bone tissue,
synthesize hormones, transmit nerve impulses, contract and relax muscles, and protect against
harmful free radicals in the body that can cause health problems such as cancer.
Vitamins
The thirteen vitamins are categorized as either water-soluble or fat-soluble. The water-soluble
vitamins are vitamin C and all the B vitamins, which include thiamine, riboflavin, niacin,
pantothenic acid, pyridoxine, biotin, folate and cobalamin. The fat-soluble
1.2.3 49290 vitamins are A, D, E, and K. Vitamins are required to perform many functions in
the body such as making red blood cells, synthesizing bone tissue, and playing a role in normal
vision, nervous system function, and immune system function.
Table 1.2 Vitamins and Their Major Functions Vitamins Major Functions
Water-soluble Thiamin (B1) Coenzyme, energy
metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance
Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5)
Coenzyme, energy metabolism assistance Pyridoxine (B6)
Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino
acid and fatty acid metabolism Folate (B9) Coenzyme, essential for
growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic
acid) Collagen synthesis, antioxidant Fat-soluble A
Vision, reproduction, immune system function D Bone and teeth health
maintenance, immune system function E Antioxidant, cell membrane
protection K Bone and teeth health maintenance, blood clotting
Vitamin deficiencies can cause severe health problems and even death. For example, a
deficiency in niacin causes a disease called pellagra, which was common in the early twentieth
century in some parts of America. The common signs and symptoms of pellagra are known as
the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better
diets relieved the signs and symptoms of pellagra, many people with the disease ended up
hospitalized in insane asylums awaiting death. Other vitamins were also found to prevent
certain disorders and diseases such as scurvy (vitamin C), night blindness vitamin A, and rickets
(vitamin D).
Protein
Carbohydrates
Fat
Vitamins
Minerals
Water
Table 1.3 Functions of Nutrients
Necessary for tissue formation, cell reparation, and hormone and
enzyme production. It is essential for building strong muscles and a
healthy immune system.
Provide a ready source of energy for the body and provide structural
constituents for the formation of cells.
Provides stored energy for the body, functions as structural components of cells and also as
signaling molecules for proper cellular communication. It provides insulation to vital organs and
works to maintain body temperature.
Regulate body processes and promote normal body-system functions.
Regulate body processes, are necessary for proper cellular function, and comprise body tissue.
Transports essential nutrients to all body parts, transports waste
products for disposal, and aids with body temperature maintenance.
This page titled 1.2: Introduction is shared under a CC BY-NC-ND 4.0 license and was authored,
remixed, and/or curated by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan Titchenal
via source content that was edited to the style and standards of the LibreTexts platform; a
detailed edit history is available upon request.
1.2.4 49290 1.1: Introduction by Jennifer Draper, Marie Kainoa Fialkowski Revilla, & Alan
Titchenal is licensed CC BY-NC-SA 4.0. Original source:
https://pressbooks.oer.hawaii.edu/humannutrition2.
1.2.5 49290 1.3: Lifestyles and Nutrition
In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle.
One facet of lifestyle is your dietary habits. Recall that we discussed briefly how nutrition affects
health. A greater discussion of this will follow in subsequent chapters in this book, as there is an
enormous amount of information regarding this aspect of lifestyle. Dietary habits include what a
person eats, how much a person eats during a meal, how frequently meals are consumed, and
how often a person eats out. Other aspects of lifestyle include physical activity level,
recreational drug use, and sleeping patterns, all of which play a role in health and impact
nutrition. Following a healthy lifestyle improves your overall health.
Figure
1.3.1
: Image by John Towner on unsplash.com / CC0
Physical Activity
In 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for
Americans[1]. The HHS states that “Being physically active is one of the most important steps
that Americans of all ages can take to improve their health. The 2008 Physical Activity
Guidelines for Americans provides science-based guidance to help Americans aged six and older
improve their health through appropriate physical activity.” The guidelines recommend exercise
programs for people in many different stages of their lifecycle. The HHS reports that there is
strong evidence that increased physical activity decreases the risk of early death, heart disease,
stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and
falls; and improves cognitive function in the elderly. These guidelines are scheduled for an
update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are
available at the website of The Canadian Society for Exercise Physiology[2].
Recreational Drug Use
Recreational drug use, which includes tobacco-smoking, electronic smoking device use, and
alcohol consumption along with narcotic and other illegal drug use, has a large impact on
health. Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease,
and several other disorders or diseases that markedly decrease quality of life and increase
mortality. In the United States, smoking causes more than four hundred thousand deaths every
single year, which is far more than deaths associated with any other lifestyle component[3].
Also, according to the Centers for Disease Control and Prevention (CDC), excessive alcohol
intake causes an estimated seventy-five thousand deaths per year[4]. Staying away from
excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver
problems, and some types of cancer. While excessive alcohol consumption can be linked to poor
health, consuming alcohol in moderation has been found to promote health such as reducing
the risk for heart disease and Type 2 diabetes in some people. The United States Department of
Health and Human Services (HHS) defines drinking in moderation as no more than one drink a
day for women and two drinks a day for men[5].
Illicit and prescription drug abuse are associated with decreased health and is a prominent
problem in the United States. The health
effects of drug abuse can be far-reaching, including the increased risk of stroke, heart disease,
cancer, lung disease, and liver disease[6].
Sleeping Patterns
Inadequate amounts of sleep, or not sleeping well, can also have remarkable effects on a
person’s health. In fact, sleeping can affect your health just as much as your diet. Scientific
studies have shown that insufficient sleep increases the risk for heart disease, Type
1.3.1 49291 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a
condition called sleep apnea, is also linked to an increased risk for chronic disease[7].
Typically, eating kosher food means a person is Jewish; eating fish on Fridays during Lent
means a person is Catholic; fasting during the ninth month of the Islamic calendar means a
person is Muslim. On New Year’s Day, Japanese take part in an annual tradition of Mochitsuki
also known as Mochi pounding in hopes of gaining good fortune over the coming year. Several
hundred miles away in Hawai‘i, people eat poi made from pounded taro root with great
significance in the Hawaiian culture, as it represents Hāloa, the ancestor of chiefs and kanaka
maoli (Native Hawaiians). National food traditions are carried to other countries when people
immigrate. The local cuisine in Hawai‘i would not be what it is today without the contributions
of Japanese, Chinese, European, and other immigrant communities.
Factors that Drive Food Choices
Along with these influences, a number of other factors affect the dietary choices individuals
make, including:
Taste, texture, and appearance. Individuals have a wide range of tastes which influence their
food choices, leading some to dislike milk and others to hate raw vegetables. Some foods that
are very healthy, such as tofu, may be unappealing at first to many people. However, creative
cooks can adapt healthy foods to meet most people’s taste.
Economics. Access to fresh fruits and vegetables may be scant, particularly for those who live in
economically disadvantaged or remote areas, where cheaper food options are limited to
convenience stores and fast food.
Early food experiences. People who were not exposed to different foods as children, or who
were forced to swallow every last bite of overcooked vegetables, may make limited food choices
as adults.
Habits. It’s common to establish eating routines, which can work both for and against optimal
health. Habitually grabbing a fast food sandwich for breakfast can seem convenient, but might
not offer substantial nutrition. Yet getting in the habit of drinking an ample amount of water
each day can yield multiple benefits.
Culture. The culture in which one grows up affects how one sees food in daily life and on
special occasions.
Geography. Where a person lives influences food choices. For instance, people who live in
Midwestern US states have less access to seafood than those living along the coasts.
Advertising. The media greatly influences food choice by persuading consumers to eat certain
foods.
Social factors. Any school lunchroom observer can testify to the impact of peer pressure on
eating habits, and this influence lasts through adulthood. People make food choices based on
how they see others and want others to see them. For example, individuals who are surrounded
by others who consume fast food are more likely to do the same.
Conclusion
Health concerns. Some people have significant food allergies, to peanuts for example, and need
to avoid those foods. Others may have developed health issues which require them to follow a
low salt diet. In addition, people who have never worried about their weight have a very
different approach to eating than those who have long struggled with excess weight. Emotions.
There is a wide range in how emotional issues affect eating habits. When faced with a great
deal of stress, some people tend to overeat, while others find it hard to eat at all.
Green food/Sustainability choices. Based on a growing understanding of diet as a public and
personal issue, more and more people are starting to make food choices based on their
environmental impact. Realizing that their food choices help shape the world, many individuals
are opting for a vegetarian diet, or, if they do eat animal products, striving to find the most
“cruelty-
1.3.2 49291 free” options possible. Purchasing local and organic food products and items
grown through sustainable processes also helps shrink the size of one’s dietary footprint.
People choose a vegetarian diet for various reasons, including religious doctrines, health
concerns, ecological and animal welfare concerns, or simply because they dislike the taste of
meat. There are different types of vegetarians, but a common theme is that vegetarians do not
eat meat. Four common forms of vegetarianism are:
1. Lacto-ovo vegetarian. This is the most common form. This type of vegetarian diet
includes the animal foods eggs and dairy products. 2. Lacto-vegetarian. This type of
vegetarian diet includes dairy products but not eggs.
3. Ovo-vegetarian. This type of vegetarian diet includes eggs but not dairy products.
4. Vegan. This type of vegetarian diet does not include dairy, eggs, or any type of animal
product or animal by-product.
References
1. U.S. Department of Health and Human Services' Office of Disease Prevention and Health
Promotion. Physical Activity. https://health.gov/paguidelines/↵
2. Canadian Society for Exercise Physiology. http://www.csep.ca/english/view.asp?x=804↵
3. Centers for Disease Control and Prevention (2020, April 28). Tobacco and Mortality.
http://www.cdc.gov/tobacco/data_statistics/fact_sheets/health_effects/tobacco_related_mortali
ty/Index.htm. ↵ 4. Centers for Disease Control and Prevention (2020, January 3). Underage
Drinking.http://www.cdc.gov/healthyyouth/alcoholdrug/↵ 5. U.S. Department of Health
and Human Services and U.S. Department of Agriculture (2015, December). 2015 – 2020
Dietary Guidelines for Americans. 8th Edition. https://health.gov/our-work/food-nutrition/2015-
2020-dietary-guidelines/guidelines/↵ 6. National Institute on Drug Abuse (2017, March 23).
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