HUMAN NUTRITION assignment

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1 Learning Outcomes After reading this chapter, you will be able to:

1.1 Discuss the factors that drive our food choices.

1.2 Define the term nutrition and characterize nutrients.

1.3 Explain the primary roles of the six classes of nutrients found in food.

1.4 Describe the best approach to meeting your nutritional needs.

1.5 Summarize three ways in which diet influences health.

1.6 Summarize the ABCD method used to assess the nutrient status of individuals and populations.

1.7 Discuss the current nutritional state of the average American diet.

1.8 Describe the scientific method that leads to reliable and accurate nutrition information.

1.9 Explain how to identify reliable nutrition infor- mation and how to recognize misinformation.

True or False? 1. Food choices are driven primarily by flavor. T/F 2. Nutrition is the study of dietary

supplements. T/F 3. Carbohydrates provide our main source of energy. T/F 4. Alcohol is a nutrient. T/F 5. Taking a dietary supplement is the only way to meet your nutrient needs. T/F 6. The most effective method of nutritional assessment is to ask clients to write down what they’ve eaten in the last 24 hours. T/F 7. About 25 percent of all Americans are obese. T/F 8. Eliminating all fat from the diet will

reduce your risk of developing heart disease. T/F 9. Cancer is the leading cause of death in the United States. T/F

10. You can get good nutrition advice from anyone who calls him- or herself a nutritionist. T/F See page 36 for the answers.

What Is Nutrition?

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4 Chapter 1 | What Is Nutrition?

What Drives Our Food Choices? LO 1.1 Discuss the factors that drive our food choices.

Have you ever considered what drives your food choices? Or are you on autopilot as you stand in line at the sub shop and squint at yet another menu board? Do you enjoy some foods and eat them often, while avoiding others with a vengeance? You obviously need food to survive, but beyond your basic instinct to eat are many other factors that affect your food choices. These factors include taste and enjoyment; culture and environment; social life and trends; nutrition knowledge; advertising; time, convenience, and cost; and habits and emotions (Figure 1.1).

Taste and Enjoyment Research confirms that when it comes to making food choices, taste is the most important consideration.2,3 This shouldn’t be too much of a surprise, considering there are more than 10,000 taste buds in the mouth. These taste buds tell you that chocolate cheesecake is sweet, fresh lemon juice is sour, and a pretzel is salty. Our preferences for sweet, salty, or creamy foods may be inf luenced by our genes4 and may change as we age.5

We have a taste for fat, which may also be genetically linked.6 When fat is combined with sugar, such as in a sugar-laden doughnut, our preference for that food is even stronger.7

Texture also affects our likelihood of enjoying foods. We enjoy a f laky piecrust but dislike one that is tough; we prefer crunchy apples to mealy ones, and creamy rather than lumpy soups. Almost 30 percent of adults dislike slippery foods, such as oysters and okra.8 Researchers have suggested that people’s preferences for sweetness, high fat, and specific textures begin early in life and this makes them resistant to change.9▲ Figure 1.1 Many Factors Influence Your Food Choices

Food Choices

Advertising Social reasons

Convenience

Emotions

Time

Habits

Culture

Nutrients

Cost

Taste

TrendsNutrition knowledge

During the course of a day, we make over 200 decisions about food, from when to eat, how much to eat, and what to eat, to how the food is prepared, and even what size plate to use.1 You make these decisions for reasons you may not even be aware of. If your dietary advice comes from media sound

bites, you may receive conflicting information. Last week’s news flash announced that eating more pro-

tein would help you fight a bulging waist. Yesterday’s headline boldly announced that limiting sugary

drinks was the key. This morning, the TV news lead was a health report on the weight-loss benefits of

consuming more dietary fiber.

It can be frustrating when nutrition news seems to change daily, but the research behind this barrage

of news illustrates the progress nutrition scientists are making toward understanding what we eat and

how it affects our health. Today’s research validates what nutrition professionals have known for decades:

Nutrition plays an invaluable role in your health.

In addition to exploring the factors that affect food choice, this chapter introduces you to the study

of nutrition. Let’s begin with the basic concepts of why and what you eat, why a healthy diet is important

to your well-being, and how you can identify credible sources of nutrition information.

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What Drives Our Food Choices? 5

Culture and Environment Enjoying food is not just a physiological sensation. Other factors, such as our culture and the environment, also play a role in which foods we eat.10 If you were a student in Mexico, you may regularly feast on corn tortillas and tamales, as corn is a staple of Mexican cuisines. In India, meals commonly include lentils with rice and vegetables, whereas Native Americans often enjoy stews of mutton (sheep), corn, vegetables, and berries. And, in Asian countries, rice likely would be front and center on your plate.

The environment in which its people live significantly influences a culture’s cuisine. This includes the climate and soil conditions as well as the native plants and animals and the distance people live from rivers, lakes, or the ocean. Foods that are available and acces- sible are more likely to be regularly consumed than foods that are scarce. For example, native Alaskans feast on fish because it is plentiful, but eat less fresh produce, which is difficult to grow locally. For most Americans today, global food distribution networks have made eating only locally available foods less of an issue than in the past; however, the tendency persists for some food items.

Our food environment—the variety of food choices available, the size and shape of plates and glassware, the packaging of foods, and the types and amounts of food that are visible—has a strong influence on what and how much we consume. We eat more food when the serving plates are larger and drink less when beverages are served in taller glasses. Environmental cues also affect eating patterns. You are more likely to linger over a meal when the light is dimmed,11 or quickly finish your meal when you are standing rather than sitting. Physical cues, such as a friend’s empty appetizer plate covered with disposed-of cocktail sticks, may signal you to eat more of your appetizer.

Social Life and Trends Every year on the fourth Thursday in November, approximately 48 million turkeys are consumed when Americans gather with family and friends to celebrate Thanksgiving.12 A person is likely to eat more on Thanksgiving than on any other Thursday, and this is partly because of the number of people eating with them. Eating dinner with others has been shown to increase the size of the meal by over 40 percent, and the more people present at the meal, the more you’ll eat.13

Eating is an important way to bond with others. Sharing a meal with family or friends stimulates conversation, creates traditions, and expands our food experiences. Although eat- ing a quick meal in the campus cafeteria may not provide you the most healthy food options, it will allow you to socialize with classmates.

For many people, activities such as watching a football game with fellow fans or going to a movie with friends often involve particular foods. More pizzas are sold on Super Bowl Sunday than on any other day of the year.14 Movie theater owners bank on their patrons buying popcorn, candy, and beverages at the concession stand before heading in to watch the film.15

Food choices are also affected by popular trends. For instance, home cooks in the 1950s bought bags of “newfangled” frozen vegetables in order to provide healthy meals in less time. A few decades later, vegetables went upscale and consumers bought them as part of ready-to-heat stir-fry mixes. Today, shoppers pay a premium for bags of fresh veggies, like carrots, that have been prewashed and peeled, sliced, or diced, and they pay even more if the food is labeled “organic.” In 2013 alone, Americans spent more than $35 billion on organic foods.16 Millennials (people born between about 1980 and 2000) who are parents are the biggest group of consumers buying organic foods.

Roughly one in three Americans is of Hispanic, Native American, Asian, or African descent. Cultural food preferences often influence food choices.

Eating junk food while watching sports or attending a sporting event sometimes seems like an American way of life.

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6 Chapter 1 | What Is Nutrition?

Food sustainability and food waste are also topics that are on the radar of restaurant patrons and shoppers, who may choose vegetarian meals or smaller portions out of concerns for the environment. Supermarkets provide dozens of choices in flavored and enhanced bottled teas and waters, which are trendy beverages among college students. As food manufacturers pour more money into research and development, who knows what tomorrow’s trendy foods will be?

Nutrition Knowledge Individuals may choose certain foods they associate with good health or avoid other foods they associate with poor health. For example, many Americans consume vegetables, fruits, and whole

grains because they perceive them as healthy choices that can help them control their blood pressure or reduce their risk of colon cancer.17 At the same time, many Americans worry about fried foods causing heart disease.

When it comes to weight management, some consumers believe that specific dietary components are the culprits behind weight gain. While 3 in 10 consumers believe that overeating any type of food will cause weight gain, one in four believe that sugar is more likely to cause you to pack on the pounds.18

The more aware you are of the effects of food choices on health, the more likely you are to make an effort to improve those choices. If you believe that choosing low-sodium foods will decrease your blood pressure or that eating yogurt with active cultures will improve your digestion, you are more likely to choose these foods. Many consumers are label-reading in the supermarket, checking the expiration date, Nutrition Facts panel, and ingredients list before buying a food product.19

Advertising The food and beverage industry spends over $136 million annually on advertising.20 Food companies spend these large sums on advertising for one reason: It works, especially on young people. American children view an estimated 30 hours of food commercials on the television annually, and more than half of these advertisements are for unhealthy foods.21

In contrast, commercials for fruits and vegetables are rare, which is unfortunate because healthy foods can be successfully marketed. The Fruit and Vegetable (FNV) campaign, the brainchild of the Partnership for a Healthier America (PHA), a nonprofit organization working with public, private, and nonprofit leaders to develop strategies to end childhood obesity, knows that celebrity marketing to kids is powerful. They recruited influential actors and athletes, all pro bono, to get kids to chow down more produce. Their research showed that 70 percent of individuals who were aware of FNV stated that they purchased and ate more fruits and vegetables after seeing or hearing about the campaign.22

Time, Convenience, and Cost When it comes to making a meal, time is often at a premium. A recent survey reported that close to 60 percent of Millennials spend as little as 15 minutes cooking dinner during the week.23 Consequently, supermarkets are now offering more prepared and partially prepared foods. If chicken is on the menu tonight, you can buy it uncooked at the meat counter in the supermarket, or you can go to the deli and buy it hot off the rotisserie, cooked and stuffed with bread crumbs or grilled with teriyaki sauce. Rice or pasta side dishes and cooked vegetables are also available to complete the meal.

The USDA certifies that foods labeled “organic” are grown without the use of toxic and persistent pesticides or fertilizers.

Rates of fruit and vegetable consumption increased among consumers exposed to the FNV advertising campaign.

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What Is Nutrition? 7

Convenience has also become more of a factor in food selection. Foods that are easily accessible to you are more likely to be eaten. Decades ago, the most convenient way to get a hot cup of coffee was to brew it at home. Today, Americans are more likely to get their latte or half-caff from one of the 29,000 coffee shops across the United States.24

For reasons related to both time and convenience, people eat out more often today than they did a few decades ago. In the 1970s, Americans spent less of their household budget on eating out, compared with today.25 Because cost is often an issue when con- sidering where to eat out, most meals consumed away from home are fast food, which is often cheaper and quicker than more nutritious meals. Though cheap fast food may be easy on the pocketbook, it is taking its toll on the health of Americans. Epidemiological research suggests that low-cost, high-calorie diets, such as those that incorporate lots of burgers, fries, tacos, and soft drinks, increase the risk of obesity, especially among those at lower socioeconomic levels.26

The good news is that cheaper food doesn’t have to always mean fast food, and when healthy foods are offered at lower prices, people do buy them. More Americans, especially urban Millennials, are opting for boxes of fresh fruits and vegetables or meal kits delivered directly to their door. They may eat home-cooked meals more often because of these services.27

Researchers have found that lowering the cost of fresh fruits and vegetables improves the consumption of these nutritious foods.28 This suggests that price reductions are an effective strategy to increase the purchase of more-healthful foods.

Habits and Emotions Your daily routine and habits often affect both when you eat and what you eat. For exam- ple, if you routinely start your day with a bowl of cereal, you’re not alone. Ready-to-eat cereals are the number-one breakfast food choice among Americans.29 Many individuals habitually snack when watching television or sitting at the computer.30

For some individuals, emotions can sometimes drive food choice: feeling happy or sad can trigger eating. In some cases, appetite is suppressed during periods of sadness or depression; in others, food is used as an emotional crutch during times of stress, depres- sion, or joy.

Although brown rice is a healthy whole-grain addition to any meal, it generally takes almost an hour to cook. For time-strapped consumers, food manufacturers have developed brown rice that cooks in 10  minutes and a precooked, microwavable variety that reheats in less than 2 minutes.

LO 1.1: THE TAKE-HOME MESSAGE Taste and enjoyment are the primary rea- sons people prefer certain foods. A food’s availability makes it more easily become part of a culture, and many foods can be regularly eaten out of habit. Advertising, food trends, limited time, convenience, emotions, and the percep- tion that foods are healthy or unhealthy also influence food choices.

What Is Nutrition? LO 1.2 Define the term nutrition and characterize nutrients.

The science of nutrition is the study of food and the nutrients we need to sustain life and reproduce. It examines the way food nourishes the body and affects health. Since its incep- tion, the science of nutrition has explored how food is digested, absorbed, transported, metabolized, and used or stored in the body. Nutritional scientists study how much we need of each nutrient, the factors that influence our needs, and what happens if we don’t consume enough. As with any science, nutrition is not stagnant. The more we discover about the relationship between nutrition and well-being, the greater the impact will be on long-term health.

nutrition Science that studies how nutrients and other components of foods nourish the body and affect body functions and overall health.

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8 Chapter 1 | What Is Nutrition?

Nutrients Are Essential Compounds in Food The body is one large organism made up of millions of cells that grow, age, reproduce, and die, all without your noticing. You slough off millions of skin cells when you towel off after a shower, yet your skin isn’t noticeably thinner today than it was last week. Your body replaces skin cells at a rate fast enough to keep you covered, and it manufactures new cells using the same nutrients found in a variety of foods. As cells die, nutrients from food provide the building blocks to replace them. Nutrients also provide the energy we need to perform all body functions and processes, from maintaining heartbeat to playing tennis.

There are six categories of nutrients found in foods and in the body: carbohydrates, lipids (fats), protein, vitamins, minerals, and water. Foods also often contain beneficial non-nutrient compounds, such as phytochemicals or zoochemicals, and nondigestible fiber, as well as chemicals added by food manufacturers to enhance color, flavor, or tex- ture or extend shelf-life.

Plant foods are made up of about 10 percent carbohydrates, fats, proteins, vitamins, and minerals (Figure 1.2). The rest is typically water, and plant foods contain more water (about 90 percent) than do animal foods (about 70 percent). Animal foods are composed of about 30 percent protein, lipids, vitamins, and minerals. One unique quality of animal foods, with the exception of dairy products, is that they do not contain any carbohydrates by the time we consume them.

A healthy human body is about 60 percent water. The other 40 percent is made up of protein and fat, as well as a small amount of stored carbohydrates, minerals in bone, and small amounts of vitamins. Thus, the old saying is true that we are what we eat, from the carbohydrates in broccoli to the proteins in meat. The six biochemical ingredients needed to sustain life are all provided by the foods in our diets.

In general, nutrients are essential—they must come from foods because either they cannot be made in the body at all, or they cannot be made in sufficient amounts to meet the body’s needs. The body can make a few nonessential nutrients in sufficient quanti- ties. An example is vitamin D, which is synthesized in the skin upon exposure to sunlight. Under some circumstances, nonessential nutrients can become essential. We refer to these nutrients as conditionally essential. If you are not exposed to enough sunlight, you will not be able to synthesize an adequate amount of vitamin D. You must then obtain vitamin D from foods and/or supplements.

Most Nutrients Are Organic Carbohydrates, proteins, lipids, and vitamins are the most complex of the six classes of nutrients. These nutrients are organic because their chemical structures contain carbon. Organic nutrients also contain the elements hydrogen and oxygen, and in the case of proteins and some vitamins, nitrogen is also part of the molecule (Figure 1.3).

Minerals are the least complex of the nutrients. From calcium to zinc, each mineral is an individual element, and its atoms are exactly the same whether found in food or in the body. For instance, the structure of zinc found in lean meats and nuts is the same as that found in a cell membrane or a hair follicle. Minerals are inorganic because, as individual elements, they do not contain carbon. Water, a three-atom molecule composed of hydrogen and oxygen, is also inorganic. The Chemistry Boost will help you visualize elements and molecules.

Some Nutrients Provide Energy All creatures need energy in order to function, and humans are no exception. Energy is defined as the capacity to do work. It also provides a source of heat. The body derives chemical energy from certain nutrients in foods, which store energy in their chemical

nutrients Compounds in foods that sustain body processes. There are six classes of nutrients: carbohydrates, fats (lipids), proteins, vitamins, minerals, and water.

essential nutrients Nutrients that must be consumed from foods because they cannot be made in the body in sufficient quantities to meet its needs and support health.

▲ Figure 1.2 Nutrients in Foods and in the Body Water is the most abundant nutrient found in foods and in the body. Carbohydrates, fats, protein, vitamins, and minerals make up the rest. Note that foods also contain non-nutritive compounds, such as phytochemicals and fiber.

Minerals

Minerals

Vitamins

Vitamins

Minerals Vitamins

Carbohydrates

Protein

Fat

Water

Human body

Protein

Fat

Water

Protein

Water

Carbohydrates

Chicken breast

59%

20%

17%

Broccoli (raw)

22%

74%

7%

89%

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What Is Nutrition? 9

bonds. During digestion and metabolism, the bonds are broken and the energy is released. This chemical energy released when the foods are digested can be converted into adenosine triphosphate (ATP), a form of energy the body can use. Carbohydrates, lipids (fats), and proteins are defined as the energy-yielding nutrients because they contribute energy to the body. Alcohol, although not a nutrient, also provides energy.

Scientists use the metric system to measure weight, volume, and distance. Grams are the fundamental units of measurement for weight; liters are the fundamental units for volume; and meters are the units used to measure distance. The metric system is a decimal system; that is, larger and smaller units are multiples or divisions of 100. For example, a kilogram is 1,000 grams (kilo = 1,000) and a centimeter is a hundredth of a meter (cent = 100). This uniform system of measurement allows scientists all over the world to share and compare data. Appendix B provides commonly used metric units.

Scientists measure the energy in foods in kilocalories. A kilocalorie is defined as the amount of energy needed to raise the temperature of one kilogram of water 1 degree

organic Describing compounds that contain carbon or carbon–carbon bonds.

nonessential nutrients Nutrients that can be made in sufficient quantities in the body to meet the body’s requirements and support health.

inorganic Describing elements or compounds that do not contain carbon.

energy Capacity to do work.

energy-yielding nutrients Three nutrients that provide energy to the body to fuel physio- logical functions: carbohydrates, lipids, and protein.

kilocalorie Amount of energy required to raise the temperature of 1 kilogram of water 1 degree centigrade; used to express the measurement of energy in foods; 1 kilocalorie is equal to 1,000 calories.

◀ Figure 1.3 The Chemical Composition of the Six Classifications of Nutrients in Food Each nutrient contains a unique combination of chemical elements.

Carbon

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

In or

ga ni

c O

rg an

ic

Hydrogen Oxygen Nitrogen Single elements

Some vitamins contain nitrogen

Carbohydrates

Lipids

Proteins

Vitamins

Minerals

Water

H ƒ

H ¬ C ¬ H ƒ

H

H ¬ O ¬ H

Methane (CH4) Water (H2O)

Chemical Bonds Most nutrients consist of carbon, hydrogen, and oxygen. These elements

combine to form compounds through chemical reactions. An atom of each element can carry a positive or negative charge and can form a set number of bonds with other elements. For example, carbon can form bonds with four elements, hydrogen can form one bond, and oxygen can form two bonds, as illustrated below. Two or more atoms bonded together are called molecules. Molecular oxygen, for example, contains two oxygen atoms (O2). Compounds are molecules containing two or more different elements. Water (H2O) is a compound. Molecules tend to be more stable than atoms, and, like atoms, can carry a positive or negative charge. Charged atoms or molecules are called ions.

Chemistry Boost

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10 Chapter 1 | What Is Nutrition?

Celsius. A kilocalorie is not the same as a calorie (with a lowercase c ), which is a much smaller unit of measurement. (In fact, a “calorie” is so small that one slice of bread con- tains about 63,000 calories.) One kilocalorie is equal to 1,000 calories.

To add to the confusion, the term Calorie (with an uppercase C ) is used on nutrition labels to express the energy content of foods and is often used in science textbooks to mean kilocalories. This text refers to the units of energy found in foods as kilocalories, abbreviated kcalories or kcals.

Each energy-yielding nutrient provides a set number of kilocalories per gram. Thus the number of kilocalories in one serving of a given food can be determined based on the amount (in grams) of carbohydrates, protein, and fat in the food. Carbohydrates and pro- tein provide 4 kilocalories per gram; so, for example, a food that contains 5 grams of car- bohydrate and 3 grams of protein would have 32 kilocalories ([5 * 4] + [3 * 4] = 32). Fats yield 9 kilocalories per gram, more than twice the number of kilocalories in either carbohydrates or protein. Alcohol contains 7 kilocalories per gram, which must be taken into account when calculating the energy of alcohol-containing foods and beverages (Figure 1.4).

Use the Calculation Corner to determine the number of kilocalories in a snack of potato chips and cola.

Energy in foods and in the body is trapped within the bonds that keep the mol- ecules together. When the bonds are broken during the process of metabolism, a sig- nificant amount of energy, including some heat, is released. The energy can then be used to digest and absorb the meal, contract muscles, fuel the heartbeat, synthesize new cells, and perform other functions. The Chemistry Boost will help you visualize covalent bonds.

People’s energy needs vary according to their age, gender, and activity level. Males generally need more energy because they weigh more and have more muscle mass (which

▶ Figure 1.4 The Energy-Yielding Nutrients and Alcohol Provide Kilocalories Carbohydrates, fats, and protein provide energy, or kilocalories, to fuel the body. Alcohol also contains kilocalories.

Carbohydrates 4 kcal/g

Alcohol 7 kcal/g

Fats 9 kcal/g

Protein 4 kcal/g

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What Is Nutrition? 11

Covalent Bonds A chemical reaction unites two atoms by creating a bond that forms a new

molecule. A covalent bond is formed when atoms share their electrons, as in the case of water. The oxygen atoms require two additional electrons and the hydrogen atoms need one electron to be stable. When these three atoms combine, the oxygen shares one electron with each of the hydrogen atoms and the hydrogen atoms share one electron with the oxygen atom. The atoms are held together because of their affinity to share each other’s electrons. The covalent bond that is formed is strong and difficult to break. Trapped within the bonds is stored energy that is released when the bonds are broken.

Chemistry Boost

O H

H

O

H H

Calculation Corner

Calculating Kilocalories in a Snack of Chips and Soda Suppose you ate an entire 8-ounce bag of potato chips and drank a 16-ounce cola while you studied for an exam. Together these two items contain 144 grams of carbohydrate (in the cola and chips), 12 grams of protein (from the chips), and 60 grams of fat (also in the chips). How many kilo- calories did you consume?

(a) To calculate the total kilocalories in this snack, multiply the total grams of each energy nutrient times the number of kilocalories per gram of that nutrient. Remember, a gram of carbohydrate and protein each contain 4 kilocalories and a gram of fat contains 9 kilocalories.

(144 g * 4 kcals/g) + (12 g * 4 kcals/g) + (60 g * 9 kcals/g) = 1,164 kcals 576 kcals + 48 kcals + 540 kcals = 1,164 kcals

In one sitting, you consumed more than 1,100 kilocalories, which for some people may be more than half of the amount they need to meet their daily energy requirement. If behaviors like this become habits, they can quickly result in weight gain.

(b) Another useful measure for assessing the nutritional quality of the snack is the percentage of fat, protein, and/or carbohydrate found in the food (you learn in later chapters that there are ranges for each nutrient that are considered part of a healthy diet). For example, what percentage of kilo- calories in the chips and soda is from fat? To answer this question, divide the fat kilocalories by the total kilocalories in the food and multiply by 100:

(540 kcals , 1,164 kcals) * 100 = 46, fat

Almost half of the kilocalories in this snack are from fat. Do you think this is likely to be a desirable proportion?

For practice, complete the same calculations for carbohydrate and protein.

Go to Mastering Nutrition and complete a Math Video activity similar to the problem in this Calculation Corner.

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12 Chapter 1 | What Is Nutrition?

requires more kilocalories to function) and less body fat. Younger people require more energy than older adults because they are still growing and therefore synthesizing more new tissue. Physically active individuals require more energy than sedentary people to fuel their activities and meet their body’s basic energy needs.

Energy that is not used to fuel the body will be stored, predominantly as fat, for later use. If you regularly consume more kilocalories than you expend, you will accumulate stored fat in adipose tissue and gain weight. The opposite is also true. Eating fewer kilo- calories than the body needs will result in the breakdown of stored energy and weight loss.

LO 1.2: THE TAKE-HOME MESSAGE Nutrition is the science of how nutrients and other components of foods nourish the body, and how the body uses nutrients to manufacture and replace cells and produce energy. Most nutrients are essential; that is, they cannot be synthesized in adequate amounts to meet body needs. Carbohydrates, lipids, proteins, and vitamins are organic nutrients composed of the chemical elements carbon, hydrogen, oxygen, and sometimes nitrogen. Minerals and water are inorganic because they don’t contain carbon. Energy in foods is measured in kilocalories. The energy-yielding nutrients—carbohydrates (4 kilocalories per gram), lipids (9 kilocalories per gram), and proteins (4 kilocalo- ries per gram)—provide fuel to be used by the body or stored for future use. Alcohol (7 kilocalories per gram) is not a nutrient but does provide energy.

Nutrient Provides Energy

Participates in Growth, Maintenance, Support, or Structure Regulates Body Processes

Macronutrients Carbohydrates Yes No No

Protein Yes Yes Yes

Fats Yes Yes Yes

Water No Yes Yes

Micronutrients Vitamins No Yes Yes

Minerals No Yes Yes

TABLE 1.1 Functions of the Major Nutrients by Type

Carbohydrates are found in a variety of foods, including breads, grains, and pasta.

What Are the Primary Roles of the Six Classes of Nutrients? LO 1.3 Explain the primary roles of the six classes of nutrients found in food.

Individual nutrients supply energy, regulate metabolism, and provide structure ( Table 1.1). Some nutrients, including carbohydrates, lipids, proteins, and water, are called macronu- trients (macro means “large”) because they are needed in much larger amounts to support normal functioning. Vitamins and minerals, though equally important to health, are con- sidered micronutrients (micro means “small”) because they are required in smaller amounts to perform their key roles. We introduce each of the six classifications of nutrients briefly in this chapter; they are discussed in much greater detail later in the textbook.

Carbohydrates Are the Primary Energy Source All forms of carbohydrates are composed of carbon (carbo-), hydrogen, and oxygen (hydrate means “water”). Carbohydrates supply simple sugar, called glucose, which is the primary source of energy for most body cells.

macronutrients Essential nutrients, including water and the energy-containing carbohydrates, lipids, and proteins that the body needs in large amounts.

micronutrients Essential nutrients the body needs in smaller amounts: vitamins and minerals.

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What Are the Primary Roles of the Six Classes of Nutrients? 13

Carbohydrates are found in most foods. Breads, cereals, nuts, fruits, legumes (dry beans, peas, and lentils), other vegetables, and dairy products are all rich in carbohydrates. The only foods that do not provide significant amounts of carbohydrates are animal products other than dairy, such as eggs, meat, poultry, and fish. (Chapter 4 covers carbohydrates in detail.)

Lipids Also Provide Energy The term lipid refers to a diverse group of organic compounds including fats (also called triglycerides), phospholipids, and sterols that are insoluble in water. These nutrients contain the same chemical elements as carbohydrates, including carbon, hydrogen, and oxygen. The difference is that lipids are much more concentrated than carbohydrates and contain less oxygen.

Triglycerides make up the majority of the lipids we eat and are found in margarine, butter, oils, and animal products. Triglycerides are an important energy source for the body, especially during rest and sleep. The body stores excess energy as triglycerides in the adipose tissue beneath the skin, which insulates the body and cushions the organs. (Chapter 5 presents more information on lipids.)

Proteins Provide the Building Blocks for Tissue Synthesis Proteins contribute the basic building blocks, known as amino acids, to synthesize, grow, and maintain tissues in the body. The tissues in muscles, bones, and skin are primarily made up of protein. Proteins also participate as neurotransmitters in the complex communication network between the brain and the rest of the body, and they play a role in the immune system and as enzymes that catalyze chemical reactions.

Proteins are similar in composition to carbohydrates and lipids in that they contain carbon, hydrogen, and oxygen. But proteins are unique in that they all contain the element nitrogen, and some also contain sulfur. Proteins can be used for energy but are usually not a primary energy source.

Protein is found in a variety of foods, including meats, dairy products, nuts, and seeds. Legumes such as soy also provide signifi- cant protein, and certain other vegetables, whole grains, and some fruits provide small amounts. (Chapter 6 covers protein in detail.)

Vitamins and Minerals Play Vital Roles in Metabolism Vitamins and minerals do not provide energy, but they are involved in numerous key functions in the body. They are essential to help regulate metabolism, for example, and without them we would be unable to convert carbohydrates, fats, and proteins to energy or to sustain numerous other chemical reactions. A deficiency of vitamins and minerals can cause a cascade of ill health effects ranging from fatigue to stunted growth, weak bones, and organ damage. The metabolic fate of carbohydrates, protein, and fats in the body depends on consuming enough vitamins and minerals in the daily diet.

Vitamins Many vitamins function as coenzymes; that is, they help enzymes catalyze reactions in the body. For example, the B vitamin thiamin attaches to and assists an enzyme involved in carbohydrate metabolism. Vitamins also activate enzymes that participate in building bone and muscle, energy production, fighting infections, and maintaining healthy nerves and vision.

There are 13 known vitamins, and each has a unique chemical structure. They are grouped into two classifications according to their solubility, which affects how they are

enzymes Proteins in living cells that act as catalysts and control chemical reactions.

coenzymes Substances, such as vitamins or minerals, that facilitate the activity of enzymes.

solubility Ability to dissolve into another substance.

Meats and dairy products are excellent sources of protein. Plant products, such as nuts, seeds, and legumes, also provide protein to the diet.

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14 Chapter 1 | What Is Nutrition?

A wide variety of fruits and vegetables are abundant sources of water-soluble vitamins.

absorbed, stored, and excreted. Water-soluble vitamins, which include vitamin C and the eight B-complex vitamins, are easily absorbed and excreted by the body and need to be consumed daily. The fat-soluble vitamins—A, D, E, and K—are stored in the liver and fatty tissues and thus don’t need to be consumed on a daily basis. (Vitamins are dis- cussed in Chapters 9 and 10.)

Minerals Minerals are inorganic elements that assist in body processes and are essential to the struc- ture of hard tissues, such as bone, and soft tissues, such as the red blood cells. Minerals like calcium and phosphorus work with protein-containing hormones and enzymes to maintain and strengthen teeth and bones. A deficiency of any of the minerals can cause disease symptoms. Falling short of daily iron needs, for example, can cause fatigue and impair your immunity.

Minerals are classified by the amount needed in the diet and total content found in the body. Major minerals are needed in amounts of at least 100 milligrams per day and are found in amounts of at least 5 grams in the body. Calcium and magnesium are two examples of major minerals. In addition to contributing to the structure of bones and teeth, some major minerals help maintain fluid balance, participate in energy meta- bolism, or contribute to muscle contractions. (Each individual major mineral is described in Chapter 12.)

Trace minerals are needed in amounts of less than 100 milligrams per day and are found in amounts of less than 5 grams in the body. Iron and zinc are two examples of trace minerals. Among other functions, trace minerals transport oxygen and carbon di oxide, participate in cell growth and development, control the metabolic rate, and play a role in body defenses. (Chapter 13 provides more specific detail on the role of trace minerals.)

Water Is Critical for Numerous Functions Some of the essential roles of water in the body probably seem obvious, as it makes up the majority of all body fluids, including digestive secretions, blood, urine, and perspi- ration. Less obvious is the fact that water is part of every cell in the body, from muscle and bone cells to brain and nerve cells. Water is also vital to several key body functions. It is essential during metabolism, for example, because it provides the medium in which metabolic reactions take place. Water functions in digestion and absorption and as a transport medium that delivers nutrients and oxygen to the cells through blood and lymph and excretes waste products through the urine and feces. Water helps maintain body temperature and acts as a lubricant for the joints, eyes, mouth, and intestinal tract. It surrounds vital organs and cushions them from injury. Because the body can’t store water, it must be replenished every day to maintain hydration. (The role of water in the body is discussed in Chapter 11.)water-soluble vitamins Vitamins that

dissolve in water; they generally cannot be stored in the body and must be consumed daily.

fat-soluble vitamins Vitamins that dissolve in fat and can be stored in the body.

major minerals Minerals found in the body in amounts greater than 5 grams; also referred to as macrominerals.

trace minerals Minerals found in the body in amounts less than 5 grams; also referred to as microminerals.

LO 1.3: THE TAKE-HOME MESSAGE The six classes of essential nutrients— carbohydrates, lipids (fats), protein, vitamins, minerals, and water—each have specific roles in the body. Carbohydrates and lipids are the body’s primary energy sources. Proteins can be used for energy, but their main role is to provide the building blocks for body structures and functional compounds. Vitamins, minerals, and water are needed to use the energy-producing nutri- ents and for various body processes.

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How Can You Be Sure to Meet Your Nutritional Needs? 15

How Can You Be Sure to Meet Your Nutritional Needs? LO 1.4 Describe the best approach to meeting your nutritional needs.

There is no question that you need all six classes of nutrients to function properly. A chronic deficiency of even one nutrient will impact the body’s ability to function in the short term. Over time, chronic deficiencies, excesses, and imbalances will affect long-term health.

Is there more to a healthy diet than just meeting your basic nutrient needs? And is there an advantage to consuming the essential nutrients through food rather than taking them as supplements?

The Best Approach Is to Consume a Balanced Diet Most credible nutrition experts will tell you that the best way to maintain nutritional health is to eat a variety of foods, including whole grains, fruits, vegetables, lean meats, and low- fat dairy. Among the reasons for this recommendation is that foods provide a variety of nutrients. For example, low-fat milk is high in carbohydrates and protein and provides a small amount of fat. Milk is also a good source of the vitamins A, D, and riboflavin, as well as the minerals potassium and calcium, and is approximately 90 percent water by weight.

Furthermore, foods almost always contain a variety of non-nutrient compounds that enhance health. Foods that are thought to provide health benefits beyond basic nutrition are known as functional foods. Americans have been consuming functional foods to improve their health since the late 1920s, when iodine was first added to salt. Today’s func- tional foods include foods such as oatmeal, genetically modified foods that are developed to have a higher nutrient content, and foods that contain or have been fortified with phytochemicals and zoochemicals.

Phytochemicals are non-nutritive chemicals that occur naturally in plants. Consum- ing a diet rich in phytochemicals is associated with a reduced risk of developing certain diseases. At least 900 different phytochemicals have been identified in foods and more are likely to be discovered. For example, lutein is found in spinach, lycopene is found in tomatoes, and anthocyanins are found in dark purple grapes. The disease-fighting properties of phytochemicals may be due to more than the compounds themselves. It is the interactions between the phytochemicals and nutrients, fiber, or other unknown substances in the food that provide the health benefits.31 Phytochemicals extracted from foods and put in a pill do not produce the same positive health effects. In contrast, foods with added phytochemicals, such as margarine with added phytosterols, have the same appearance and taste as your favorites but provide added health benefits.

Zoochemicals are naturally occurring, health-enhancing chemicals found in animal-based foods. Examples include lutein and zeaxanthin found in egg yolks, which may protect against vision disorders such as macular degeneration and the formation of cataracts. Omega-3 fatty acids added to butter substitutes may improve heart health and reduce inflammation, protecting us against heart disease, cancer, and a decline in cogni- tive function. And the beneficial bacteria (called probiotics) present in yogurt support intestinal health and function.

Table 1.2 provides a guide to functional foods. These foods can be part of a healthy, well-balanced diet. Keep in mind that whole grains, fruits, vegetables, healthy vegetable oils, lean meat and dairy products, fish, poultry, and nuts and seeds all contain varying amounts of naturally occurring phytochemicals or zoochemicals and are the quintessential functional foods. Consumers who choose packaged functional foods, such as snack bars and juices, should take care not to overconsume any one compound.

functional foods Foods that may provide additional health benefits beyond their basic nutrient value.

phytochemicals Non-nutritive plant compounds, found in fruits and vegetables, that may play a role in fighting chronic diseases.

zoochemicals Non-nutritive animal compounds that play a role in fighting chronic diseases.

Healthy eating is a way of life.

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16 Chapter 1 | What Is Nutrition?

Some Nutrient Needs Can Be Met with Fortified Foods or a Supplement Some individuals with dietary restrictions or higher nutrient needs may benefit from tak- ing a supplement if they cannot meet their nutrient requirements through whole foods alone. For example, someone who is lactose intolerant (has difficulty digesting milk prod- ucts) may have to meet his or her calcium needs from sources other than dairy products. Calcium-fortified orange juice or soymilk or a calcium supplement would be an option for such an individual. Pregnant women should take an iron supplement because their increased need for this mineral is unlikely to be met through a healthy diet alone.

Note that a balanced diet, fortified foods, and dietary supplements aren’t mutually exclusive. Some or all of these sources of nutrients, phytochemicals, and zoochemicals can be combined as the best nutritional strategy for good health.

This Compound Found in This/These Functional Food(s) May Have This Health Benefit

Beta-carotene Carrots, pumpkin, cantaloupe, broccoli Functions as an antioxidant in the body

Lycopene Tomatoes, tomato sauce May lower risk of prostate cancer

Soy protein Tofu, soy milk Lowers risk of heart disease

Beta-glucan Oatmeal, oats, oat bran Lowers blood cholesterol

Plant sterol and stanol esters Fortified margarines, like Benecol spreads Lowers blood cholesterol

Omega-3 fatty acids Salmon, sardines, tuna May reduce the risk of heart disease

Whole grains Whole-wheat bread, brown rice, popcorn May reduce the risk of some cancers and heart disease

Flavanols Dark chocolate, green apples May contribute to heart health

Anthocyanins Berries, red grapes, cherries Act as antioxidants, may contribute to brain function

Probiotics Active cultures in fermented dairy products such as yogurt

Support intestinal health

TABLE 1.2 Your Guide to Functional Foods

LO 1.4: THE TAKE-HOME MESSAGE A balanced diet providing a variety of whole foods rich in nutrients, phytochemicals, and zoochemicals reduces the risk of developing certain diseases and is the best way to meet nutritional needs. People who cannot meet their nutrient needs through food alone may benefit from consuming fortified foods and/or taking a supplement.

How Does Diet Influence Your Health? LO 1.5 Summarize three ways in which diet influences health.

Your diet can positively affect your health by reducing your risk of chronic diseases, pre- venting nutrient-deficiency diseases, and interacting in beneficial ways with your genes. Let’s look a little further at each of these three key influences.

A Healthy Diet Reduces the Risk of Chronic Disease A healthy diet reduces the risk of chronic disease. Of the top 10 leading causes of death in the United States, four are chronic diseases linked to poor nutrition. These include heart disease, cancer, stroke, and diabetes (Table 1.3). Eating well helps us achieve and maintain a healthy weight and reduce the risk for all four of these chronic diseases, which are significantly increased in people who are obese.

chronic disease Noncommunicable disease characterized by a slow onset, long duration, and gradual progression.

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How Does Diet Influence Your Health? 17

Nutrition also plays an important role in preventing other chronic diseases and conditions that can reduce quality of life. A healthy diet, for example, can help keep bones strong and reduce the risk of developing osteoporosis. Evidence also suggests that a healthy diet can reduce the risk of hypertension (high blood pressure), age-related vision loss, and many other chronic conditions.

A Healthy Diet Prevents Nutrient-Deficiency Diseases Our understanding of the link between nutrition and health began to develop several centuries ago with discoveries of the health effects of certain foods. For example, in the 1600s some seagoing merchants realized that providing their sailors with citrus fruits prevented scurvy, a disease characterized by tissue breakdown. By the year 1800, the British Navy began routinely supplying sailors with limes, and the term limey for a British sailor was born.

Although scientists had begun to recognize the value of certain foods in treating disease, it wasn’t until the early 1900s that the concept of essential nutrients was widely accepted and many vitamins and minerals were identified. For example, vitamin C, the “anti-scurvy agent” in citrus fruits, was discovered in 1912. Throughout the early decades of the twentieth century, nutrition science became more quantitative, addressing the ques- tions of how much of each nutrient is required and how individuals might vary in their nutrient needs. Nutrition research advanced further as dietary surveys conducted by the government gathered population data. As a result of these efforts, nutrient-deficiency diseases are now rare throughout the developed world.

In the twenty-first century, nutrition science has evolved to study the role of nutri- ents and functional foods not only in preventing chronic disease but also in promoting longevity. A key contribution to this evolution has been our increasing understanding of the relationship between our diet and our genes.

A Healthy Diet Can Positively Affect Gene Expression Most chronic diseases stem from the interplay between our genetic makeup and envi- ronmental factors, which include our diet (Figure 1.5). Each one of us carries a unique combination of genes—segments of DNA—that we inherited from our parents. Because genes are chemical instructions for assembling body proteins, they are responsible for our appearance, our metabolism, and our susceptibility to disease. Some genes have variations in their codes (mutations) that increase susceptibility to diseases such as cancer, cardio- vascular disease, and diabetes, whereas other gene variants enhance the body’s ability to

Disease/Cause of Death Nutrition Related

1. Heart disease X

2. Cancer X

3. Respiratory diseases

4. Accidents

5. Stroke X

6. Alzheimer’s disease

7. Diabetes X

8. Influenza and pneumonia

9. Kidney disease

10. Suicide

Source: Centers for Disease Control. 2017. Leading Causes of Death. Available at www.cdc.gov.

TABLE 1.3 Leading Causes of Death in the United States

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18 Chapter 1 | What Is Nutrition?

resist chronic disease. Variants alone rarely cause disease directly; usually, they increase the risk that the disease will develop given a conducive environment.

The interactions between genes and your environment are complex. Scientific advances point to a variety of mechanisms by which nutrition—a key aspect of the cellular environment—inter- acts with genes to influence your risk of disease. While you can’t change the genetic cards you are dealt, by improving the quality of your diet, you can change the way you play the game.

The Human Genome Project (HGP) mapped the sequence of all of the genes (the genome) in humans. Completion of the HGP has enabled nutritionists, geneticists, and other researchers to actively examine the synergistic effects of nutrition and genetics. This reaction either increases or decreases gene expression, producing greater or smaller amounts of proteins, which in turn affects body function. The study of the mechanisms by which factors such as food intake alter

gene expression without changing the DNA sequence is known as epigenetics. For exam- ple, folate, one of the B vitamins, may alter the expression of genes as the embryo develops during early pregnancy. A deficiency of folate during this critical time increases the risk of specific birth defects in the baby. We talk more about this in Chapter 10.

Until recently, nutrition research and genetic research contributed separately to our understanding of human health and disease. Studied together, these two fields help us understand how genetic variations influence an individual’s response to his or her diet (nutrigenetics), and how nutrients and other components of foods influence genetic expres- sion (nutritional genomics, or nutrigenomics).

Recent advances in nutritional genomics have already yielded potential clinical appli- cations. For example, research has shown that chronic inflammation can be reduced with consumption of certain bioactive compounds found in food. These compounds include vitamin C in fruits and vegetables, vitamin E in wheat germ and vegetable oils,32 and the omega-3 fatty acids in fish.33 Increasing dietary intake of these compounds may regulate the expression of genes coding for proteins active in inflammation.

Nutritional genomics may have tremendous potential to provide personalized dietary recommendations based on an individual’s genetic makeup. Ultimately, a future regis- tered dietitian nutritionist (RDN) may be able to use this information to recommend dietary modifications specific to a patient’s DNA.

gene expression Processing of genetic information to create a specific protein.

epigenetics Study of the variety of environmental factors and other mechanisms influencing gene expression.

nutritional genomics Study of the relationship between genes, gene expression, and nutrition.

registered dietitian nutritionist (RDN) Health professional who is a food and nutrition expert; RDNs obtain a college degree in nutrition from an Academy of Nutrition and Dietetics–accredited program and pass a national exam.

▲ Figure 1.5 Chronic Disease Is a Mixture of Genetic Influences and Our Environment

Environmental influences Diet

Physical activity

Gene variants Susceptibility genes

Chronic Disease

The study of nutritional genomics may one day allow individuals to tailor their diets to their DNA.

LO 1.5: THE TAKE-HOME MESSAGE Eating a balanced diet that includes ade- quate but not excessive amounts of all nutrients is the best way to stay healthy and reduce the risk of developing four of the top 10 leading causes of death in the United States, including heart disease, cancer, stroke, and diabetes. A healthy diet also prevents nutrient-deficiency diseases such as scurvy. In addi- tion, a healthy diet influences gene expression in ways that may increase or decrease your risk of disease.

How Do We Assess Nutritional Status? LO 1.6 Summarize the ABCD method used to assess the nutrient status of individuals and populations.

How do you know if you are eating enough of the essential nutrients? If you suspect you may not be meeting all of your nutrient needs, or you have been diagnosed with a nutrition-related disease, turn to a nutrition professional, such as an RDN. The RDN will

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How Do We Assess Nutritional Status? 19

conduct a complete assessment to find out if you are getting too much, too little, or the right amount of all nutrients.

Nutrition professionals describe a person’s state of nutrition as either healthy or malnourished. Someone who lacks a specific nutrient, or isn’t consuming enough energy, is undernourished, which means that person is at risk of losing too much weight or devel- oping a disease related to a nutrient deficiency. In contrast, an individual who overconsumes a particular nutrient, or eats too many kilocalories, is described as being overnourished. This person runs the risk of becoming overweight, developing diseases such as diabetes or heart disease, or potentially accumulating toxic amounts of a specific nutrient in the body.

The ABCD Method Is Used to Assess the Nutritional Status of Individuals Evaluating a person’s current nutrition status begins with a look at that person’s health history, including any experiences with acute or chronic illness, and diagnostic proce- dures, therapies, or treatments that may increase nutrient needs or induce malabsorption. Does the patient have a family history of diabetes or heart disease? Has the patient been overweight or underweight in the past? To learn more about evaluating your own family history, see the Self-Assessment.

malnourished Characterized by an inappropriate level of essential nutrients to maintain health; overnourishment and undernourishment are forms of malnutrition.

undernourished Characterized by an inadequate energy intake or a deficiency in quality or quantity of one or more individual nutrients.

overnourished Characterized by an excessive intake of energy or one or more individual nutrients.

acute Characterized by a sudden onset and rapid progression of symptoms.

malabsorption Condition characterized by impaired absorption of nutrients through the gastrointestinal tract.

Along with the health history, nutrition professionals use a number of specialized methods to assess the nutritional status of individuals. You can use the mnemonic ABCD to help you remember these methods, which include collecting anthropometric data, collecting biochemical (laboratory) data, conducting a clinical exam, and performing dietary intake assessments ( Table 1.4). ABCD is more of a framework than a chronological guideline. Each portion builds off the other, but it is not necessary to conduct the method in any specific order.

Assessing Dietary Intake through Questionnaires and Interviews Questioning an individual about his or her dietary intake and diet history is an important aspect of a nutrition assessment. A detailed diet history is conducted by a skilled inter- viewer who knows just what types of questions to ask to help a patient remember not only current food intake but food intake in the past.

Two tools used to collect dietary intake data are questionnaires and interviews. Food frequency questionnaires and food records can be used to gather information about how often a specific food or category of food is eaten. A nutrition interview can reveal data about lifestyle habits, such as how many meals are eaten daily, where they are eaten, and who prepares them.

Self-Assessment

How Healthy Is Your Family Tree? You inherited your DNA from your parents, so the extent to which DNA affects health is largely hereditary. Does your family have a history of heart disease, diabetes, or obesity? What about other chronic diseases or conditions? Before you learn about the role that healthy eating plays in preventing chronic diseases, ask your parents and grandparents about your family’s health history. If there are certain diseases or conditions that run in your family, you’ll want to pay particular attention to these as you learn more throughout this text.

An easy way to gather information about your family’s health history is by visiting My Family Health Portrait at http://familyhistory.hhs.gov. The site generates a family tree report according to the medical history you enter. Save a copy of the report for future reference.

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20 Chapter 1 | What Is Nutrition?

weight, as well as how a child’s height and weight compare with others of the same age. All of these measurements are easily obtained with a scale and tape measure.

The BMI is a measure of weight relative to height, and waist circumference measures abdominal fat. Body composition measurements can provide data on an individual’s lean body tissue and percentage of body fat. The measurements can be assessed with special- ized equipment, such as skin calipers or the Bod Pod. (We discuss these measurements in greater detail in Chapter 14.)

Data collected from anthropometric measurements is then compared with reference standards. Patterns and trends become evident when more than one measurement is taken over time and compared with the initial values. By combining the results of the BMI and waist circumference with other information gathered during the nutrition assessment, an individual’s risk of developing diseases associated with obesity, such as diabetes and heart disease, can be determined.

Conducting a Clinical Examination A person who is malnourished will exhibit physical symptoms as the body adjusts to the lack or excess of nutrients. Therefore, several parts of the body can be inspected during a clinical exam for evidence of malnutrition. Observing the hair, skin, eyes, fingernails, tongue, and lips can provide clues that point to under- or overnutrition. For example, cracks at the corners of the mouth can be evidence of B-vitamin deficiencies, whereas small pinpoint hemorrhages on the skin may reflect a deficiency of vitamin C. Observations of physical symptoms should be followed up by more direct measurements, including laboratory assessments.

Collecting Biochemical Data Laboratory tests based on body fluids, including blood and urine, can be important indicators of nutritional status, but they are also influenced by non-nutritional factors. Biochemical tests of urine assess nutritional status by measuring, for example, how fast a nutrient is excreted through the urine and the metabolic by-products of various nutrients found in urine. Blood tests may measure levels of albumin (a blood protein) to screen for protein deficiency; low hemoglobin levels in the blood indicate iron-deficiency anemia; and a high fasting blood sugar level may suggest diabetes.

Surveys Are Used to Assess the Nutritional Status of a Population Group Assessing the nutritional status of an individual in a clinical setting is one thing, but how do we determine the nutritional status of a population? What percentage of Americans is meeting the dietary recommendations for healthy eating? To find out, researchers col- lect dietary intake information on a large scale. The information is used by researchers in many ways, such as to determine the adequacy of the current nutrient recommendations for different population groups, to evaluate and develop food assistance programs, and to assess risk of nutritional deficiencies.

Populations are typically assessed through the use of surveys. Numerous national surveys have been developed by a variety of federal agencies to assess the health and nutritional status of Americans. The National Health and Nutrition Examination Survey (NHANES) is one of the most prominent. Conducted annually, it is used to determine the nutritional status of Americans of all ages and to monitor their risk behaviors over time. The intake of carbohydrates, lipids, protein, vitamins, minerals, and fiber is collected using a 24-hour recall method and reported in the document What We Eat in America.

The Framingham Heart Study, which coined the term risk factors, had a major impact on the dietary intake of Americans. This study used surveys to collect longitudinal data on two generations and more than 10,000 participants to establish the current recommenda- tions for the prevention of cardiovascular disease.

body mass index (BMI) Measurement calculated using the metric formula of weight in kilograms divided by height in meters squared; used to determine whether an individual is underweight, at a healthy weight, overweight, or obese.

One of the easiest ways to determine an individual’s intake of nutrients is to use the food frequency questionnaire (FFQ). This form of assessment provides evidence of consump- tion patterns over time. For example, if you wanted to determine the usual calcium intake over time of an older woman with osteoporosis, an FFQ could be used to indicate the number of servings of dairy foods “per day, per week, and per month,” as well as whether she “seldom” or “never” consumes milk, cheese, or yogurt. The FFQ is a reasonably reli- able, accurate, and inexpensive method to assess usual intake.34

This assessment tool is not as helpful in assessing the actual amount consumed of a nutrient, nor does it always accurately reveal usual intake. For that information, a food record or 24-hour dietary recall usually provides a better picture.35

A food record is simply a diary of what foods and beverages are eaten, how much, and when they are eaten over a defined period of time. Food records are often kept for 3–7 days and are considered by some to be one of the best methods for collecting diet information. There are drawbacks to this method. The accuracy depends on the individual’s skill and com- mitment to keeping a valid record. Many people start out strong and then lose interest or simply forget to record the food. Or, they might alter their usual food intake to avoid feeling embarrassed about what they eat.

Food records can be kept in written form, such as a journal, or with an electronic diet analysis program. There are also new digital and mobile devices that may help improve the accuracy, ease, and evaluation of recording dietary intake.36

The FFQ or a diet record should be selected based on the specific information the assessor needs to know, such as iron intake over time and how much iron the individual eats daily, as well as the assessor’s ability to complete the instrument accurately. The information obtained from these tools is then compared with current dietary standards, which we discuss in the next chapter.

The 24-hour dietary recall method is a quick assessment conducted by a trained interviewer who asks a patient to recall all the food and drinks, including snacks, eaten the previous day. This tool relies on the skills of the interviewer and the individual’s ability to remember what he or she ate and drank the day before. Because dietary intake varies from one day to the next, one 24-hour period may not provide an accurate estimate of typical intake.

Collecting Anthropometric Data Data about body size or body composition is also called anthropometric data. In adults, this usually means height, weight, body mass index (BMI), waist-to-hip ratios, and waist circumference. For children, growth charts have been developed that compare height to

Type of Assessment Measurements What They Determine

Anthropometric Height Weight Body mass index Waist-to-hip ratio Waist circumference

Growth, obesity, changes in weight, and risk of developing chronic diseases such as diabetes and heart disease

Biochemical Blood, urine, and feces Protein, mineral, and vitamin status and disease

Clinical Observe hair, fingernails, skin, lips, mouth, muscles, joints, overall appearance

Signs of deficiencies and excesses of nutrients

Dietary Intake Diet history Diet record Food frequency questionnaire 24-hour dietary recall

Usual nutrient intake and deficiencies or excesses of various nutrients

TABLE 1.4 The ABCDs of Nutrition Assessment

Whether a handwritten log or a smartphone app, food diaries can be useful tools for assessing nutritional status.

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How Do We Assess Nutritional Status? 21

weight, as well as how a child’s height and weight compare with others of the same age. All of these measurements are easily obtained with a scale and tape measure.

The BMI is a measure of weight relative to height, and waist circumference measures abdominal fat. Body composition measurements can provide data on an individual’s lean body tissue and percentage of body fat. The measurements can be assessed with special- ized equipment, such as skin calipers or the Bod Pod. (We discuss these measurements in greater detail in Chapter 14.)

Data collected from anthropometric measurements is then compared with reference standards. Patterns and trends become evident when more than one measurement is taken over time and compared with the initial values. By combining the results of the BMI and waist circumference with other information gathered during the nutrition assessment, an individual’s risk of developing diseases associated with obesity, such as diabetes and heart disease, can be determined.

Conducting a Clinical Examination A person who is malnourished will exhibit physical symptoms as the body adjusts to the lack or excess of nutrients. Therefore, several parts of the body can be inspected during a clinical exam for evidence of malnutrition. Observing the hair, skin, eyes, fingernails, tongue, and lips can provide clues that point to under- or overnutrition. For example, cracks at the corners of the mouth can be evidence of B-vitamin deficiencies, whereas small pinpoint hemorrhages on the skin may reflect a deficiency of vitamin C. Observations of physical symptoms should be followed up by more direct measurements, including laboratory assessments.

Collecting Biochemical Data Laboratory tests based on body fluids, including blood and urine, can be important indicators of nutritional status, but they are also influenced by non-nutritional factors. Biochemical tests of urine assess nutritional status by measuring, for example, how fast a nutrient is excreted through the urine and the metabolic by-products of various nutrients found in urine. Blood tests may measure levels of albumin (a blood protein) to screen for protein deficiency; low hemoglobin levels in the blood indicate iron-deficiency anemia; and a high fasting blood sugar level may suggest diabetes.

Surveys Are Used to Assess the Nutritional Status of a Population Group Assessing the nutritional status of an individual in a clinical setting is one thing, but how do we determine the nutritional status of a population? What percentage of Americans is meeting the dietary recommendations for healthy eating? To find out, researchers col- lect dietary intake information on a large scale. The information is used by researchers in many ways, such as to determine the adequacy of the current nutrient recommendations for different population groups, to evaluate and develop food assistance programs, and to assess risk of nutritional deficiencies.

Populations are typically assessed through the use of surveys. Numerous national surveys have been developed by a variety of federal agencies to assess the health and nutritional status of Americans. The National Health and Nutrition Examination Survey (NHANES) is one of the most prominent. Conducted annually, it is used to determine the nutritional status of Americans of all ages and to monitor their risk behaviors over time. The intake of carbohydrates, lipids, protein, vitamins, minerals, and fiber is collected using a 24-hour recall method and reported in the document What We Eat in America.

The Framingham Heart Study, which coined the term risk factors, had a major impact on the dietary intake of Americans. This study used surveys to collect longitudinal data on two generations and more than 10,000 participants to establish the current recommenda- tions for the prevention of cardiovascular disease.

body mass index (BMI) Measurement calculated using the metric formula of weight in kilograms divided by height in meters squared; used to determine whether an individual is underweight, at a healthy weight, overweight, or obese.

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22 Chapter 1 | What Is Nutrition?

How Healthy Is the Average American Diet? LO 1.7 Discuss the current nutritional state of the average American diet.

The food supply in the United States provides an array of nutritious choices to meet the dietary needs of Americans. Fresh fruits and vegetables, whole grains, lean meats, fish, and poultry are easily accessible and affordable through local grocery stores and farmers markets. With such an abundance of healthy foods to choose from, are Americans adopt- ing healthy diets?

The Quality of the American Diet Needs Improvement In general, the American diet is too high in added sugars, sodium, and saturated fat.37 Added sugars account for 13 percent of America’s daily kilocalories. This is largely due to Americans’ love of soft drinks, other sugary beverages, and sweets and treats.38 High sodium intake is a risk factor for hypertension, and Americans consume far more than is recommended. The American diet also contains too much saturated fat, the form of fat linked to cardiovascular disease. Whereas the recommended intake is to consume less than 10 percent of your total daily kilocalories from saturated fat, Americans, on average, are consuming over 11 percent. However, most Americans don’t exceed the recommended dietary cholesterol intake limit of 300 milligrams per day.39

In contrast, our intake of fiber and certain vitamins and minerals is too low.40 Our low fiber intake is partly due to inadequate consumption of fruits and vegetables and overconsumption of refined grains, which provide far less fiber than whole grains. (The role of dietary fiber in health is discussed in Chapter 4.) American women fail to meet their recommended intake for iron, and Americans in general don’t consume enough vitamin D, potassium, and calcium.41 In an attempt to balance their poor choice in foods, over 50 percent of Americans take at least one vitamin or mineral supplement per day.42

Our lack of a healthy diet may be due in part to where we eat and with whom we eat. Today, many Americans eat most of their meals away from home.43 Some of us eat in the car or buy takeout meals or prepared foods from the supermarket. Research suggests that increasing the number of meals consumed as a family may improve the dietary quality of the entire family. Eating family meals together seven or more times per week has been associated with consuming an additional serving of both fruits and vegetables daily as compared with families who do not dine together.44

The majority of Americans understand the positive benefits of eating breakfast, yet nearly 25 percent of Americans skip this morning meal.45 Breakfast, which often includes foods from the dairy, grains, and fruit groups, is an important meal that could provide Americans with fiber (whole-grain cereal), vitamin D and calcium (milk), and potassium

added sugars Sugars added to foods during processing and/or packaging.

LO 1.6: THE TAKE-HOME MESSAGE An individual’s nutritional status is assessed by gathering information from health history, dietary record, and anthropometric, clinical, and biochemical (laboratory) data. When the information from the ABCD methods is viewed together, a comprehensive picture of the individual’s nutritional status can be determined. The National Health and Nutrition Examination Survey is used to determine the nutritional status of a large population. The Framingham Heart Study provided the foundation for the current dietary recommendations for heart health.

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How Healthy Is the Average American Diet? 23

(bananas, orange juice). Many Americans are falling short of fiber and these three nutrients in their daily diet.

Rates of Overweight and Obesity in Americans Are Too High As Americans take in more kilocalories than they burn in their sedentary lives, they create a recipe for overweight and obesity. Overall, more than 35 percent of American adults are obese.46 Rates within certain populations and geographical regions are even higher (Figure 1.6). Along with these increases in obesity have come higher rates of type 2 diabetes, particularly among children, and increased rates of heart disease, cancer, and stroke. Reducing America’s obesity rate is therefore a top public health priority.

Healthy People 2020 Provides Health Objectives for Americans The U.S. Surgeon General has issued calls for a nationwide health improvement program since 1979. The latest edition of this report, Healthy People 2020, contains a set of health objectives for the nation to achieve over the second decade of the twenty-first century.47

There are more than 35 topic areas in Healthy People 2020, rang- ing from ensuring that Americans have adequate access to health services to improvements in their diet and physical activity. Objec- tives are developed within each topic area. For example, research indicates that Americans’ body weights are increasing rather than decreasing. Thus, “Nutrition and Weight Status” is one topic area. The numerous objectives developed within this topic area, if ful- filled, will help Americans improve their diet and reduce their weight and their risk for chronic disease. Table 1.5 lists a few objec- tives in this topic area.

As you can see from the table, consuming adequate amounts of fruits and vegetables is beneficial to managing one’s weight. Americans should increase their intake of both of these food sources to help them improve their nutrition and weight status.

▲ Figure 1.6 Obesity Trends Among U.S. Adults Over the past few decades, rates of obesity have risen significantly in the United States. Source: Centers for Disease Control. 2016. “Prevalence of Self-Reported Obesity among U.S. Adults.” Available at www.cdc.gov.

a

b

Objectives Target for Americans (%) Status of Americans (%)

Increase the proportion of adults who are at a healthy weight 33.9 30.8

Reduce the proportion of adults who are obese 30.5 33.9

Reduce the proportion of children and adolescents ages 2–19 who are considered obese

14.5 16.1

Increase the contribution of fruits to diets of the population age 2 years and older

0.9 cups/1,000 kcals 0.5 cups/1,000 kcals

Increase the variety and contribution of vegetables to the diets of the population age 2 years and older

1.1 cups/1,000 kcals 0.8 cups/1,000 kcals

Source: United States Department of Health and Human Services. Nutrition and Weight Status: Objectives. Updated January 12, 2017. Healthy People 2020. Available at www.HealthyPeople.gov. Accessed January 2017.

TABLE 1.5 Healthy People 2020 Nutrition and Weight Status Objectives

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24 Chapter 1 | What Is Nutrition?

What Is Credible Nutrition Research? LO 1.8 Describe the scientific method that leads to reliable and accurate nutrition information.

If you Google the word nutrition, you will get a list of about 14.5 million entries in 0.25 sec- onds. Obviously, the world is full of nutrition information at our fingertips. But is it credible?

Anyone who has attempted to lose weight can probably tell you how hard it is to keep up with the latest diet advice—because it seems to keep changing. In the 1970s, waist watchers were told that carbohydrates were the bane of their existence and that a protein-rich, low-carbohydrate diet was the key to shrinking their waistline. A decade later, avoiding fat was the way to win the battle of the bulge. By 2000, carbohydrates were being ousted again, and protein-rich diets were back in vogue. More recently, high-protein diets have been losing popularity and high-carbo- hydrate diets are once again being promoted for weight loss. So . . . are you frustrated yet?

Whereas diet trends and popular wisdom seem to change fre- quently, basic scientific knowledge about nutrition does not. Results from individual studies are often deemed newsworthy and publicized in the media, but the results of one report do not radically change expert opinion. Only when multiple, affirming research studies have been con- ducted is a consensus reached about nutrition advice. News of the results of one study is just that: news. In contrast, advice from an author-

itative health organization or committee, such as the American Heart Association or the Dietary Guidelines Advisory Committee, which is based on a consensus of research infor- mation, is sound information that can be trusted for the long term.

Sound Nutrition Research Begins with the Scientific Method Sound research studies begin with a process called the scientific method. Scientists observe something in the natural world, ask questions, and propose an explanation (or hypothesis) based on their observations. They then test their hypothesis by conducting an experiment. There are many steps in the scientific method and many adjustments are made along the way before a scientist has gained enough information to draw a conclusion about his or her hypothesis. In fact, the entire process can take years to complete.

Let’s walk through a nutrition-related study in which scientists used the scientific method to study rickets (Figure 1.7). Rickets is a disease in children in which the leg bones are so weakened that they cannot hold up the child’s body weight. The legs bow as a result. In the early 1800s, parents often used cod-liver oil to treat rickets because it seemed to provide a miraculous cure.

consensus Agreed-upon conclusion of a group of experts based on a collection of information.

scientific method Process used by scientists to gather and test information for the sake of generating sound research findings.

hypothesis Idea or explanation proposed by scientists based on observations or known facts.

LO 1.7: THE TAKE-HOME MESSAGE The American diet is too high in added sugars, sodium, and saturated fat, and too low in dietary fiber, vitamin D, potassium, and calcium. Rates of overweight and obesity among Americans are too high. Incidences of overweight and obesity among Americans are prevalent, yet many people are falling short of some nutrient needs. Healthy People 2020 is a set of health objectives for the nation to achieve over the second decade of the twenty-first century.

Nutrition-related stories often lead in newspa- pers and magazines and on websites.

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What Is Credible Nutrition Research? 25

Scientists noticed the cod-liver oil curing phenomenon and asked themselves why cod-liver oil cured rickets. In doing so, these scientists were using the first step in the scientific method: observing and asking questions.

The second step of the scientific method is to formulate a hypothesis. Because cod- liver oil is very rich in vitamin A, scientists initially thought that this vitamin was the curative factor. To confirm this, scientists proceeded to the third step, which was to conduct an experiment.

The scientists altered the cod-liver oil to destroy its vitamin A. The altered oil was given to rats that had been fed a diet that caused rickets. Surprisingly, the rats were still cured of rickets. This disproved the scientists’ original hypothesis that vitamin A was the curative factor. They then needed to modify their hypothesis, as it was obvious that there was something else in the cod-liver oil that cured rickets. They next hypothesized that it was the vitamin D in the oil that cured the rats. They conducted another experiment to confirm this hypothesis, which it did.

What good would it be to make such an important discovery if other scientists couldn’t find out about it? Fortunately, scientists today share their findings by summarizing and submitting their research to a peer-reviewed journal (Figure 1.8). Other scientists (peers) review the researchers’ findings to make sure that they are sound. If so, the research study is published in the journal. After that, it may be picked up by the popular press and reported. If the relationship between vitamin D and rickets were discovered today, it would probably be the lead story on CNN.

As more and more studies confirmed that vitamin D could cure and prevent rickets, a theory developed. By the 1920s, researchers knew with great certainty that vitamin D prevents rickets, and that a deficiency of vitamin D can cause deformed bones in children. Because of this, there is a consensus among health professionals as to the importance of vitamin D in the diets of children.

peer-reviewed journal Journal in which scientists publish research findings, after the findings have gone through a rigorous review process by other scientists.

◀ Figure 1.7 Steps of the Scientific Method The scientific method is used to conduct credible research in nutrition and other scientific fields.

Observe and ask a question Why does cod-liver oil cure rickets?

Hypothesis supported Rats were not cured.

Hypothesis not supported Rats were cured.

Revise or formulate a new hypothesis

Conduct an experiment Feed rats with rickets cod-liver oil that contains no vitamin A.

Formulate a hypothesis The vitamin A in cod-liver oil is the curative factor.

▲ Figure 1.8 A Hypothesis Can Lead to a Scientific Consensus When a hypothesis is supported by research, the results are published in peer-reviewed journals. Once a theory has been developed and supported by subsequent experiments, a consensus is reached in the scientific community.

Hypothesis supported

Publish findings

Develop theory

Establish consensus

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26 Chapter 1 | What Is Nutrition?

Scientists Use a Variety of Experiments to Test Hypotheses Scientists can use different types of experiments to test a hypothesis. A laboratory exper- iment is done within the confines of a lab setting, such as the rickets experiments with rats. Research conducted with humans is usually observational or experimental.

Observational research involves exploring factors in two or more groups of sub- jects to see if there is a relationship to a certain disease or health outcome. One type of observational research is epidemiological research, which looks at health and disease in populations of people. For example, scientists may notice that there is a higher incidence of rickets among children who live in Norway than among children who live in Australia. Through their observations, they may find a relationship between the lack of sun exposure in Norway and the high incidence of rickets there compared with sunny Australia. How- ever, the scientists can’t rule out that the difference in the incidence of rickets in these two populations may also be due to other factors in the subjects’ diet or lifestyle. This type of research does not answer the question of whether one factor directly causes another.

Experimental research involves at least two groups of subjects. One group, the experimental group, is given a treatment, and another group, the control group, isn’t. When scientists hypothesized that vitamin D cured rickets, they would have randomly assigned children with rickets to one of two groups (Figure 1.9). The scientists would have

laboratory experiment Scientific experiment conducted in a laboratory; some involve animals.

observational research Research that involves systematically observing subjects to see if there is a relationship to certain outcomes.

epidemiological research Research that studies the variables that influence health in a population; it is often observational.

experimental research Research involving at least two groups of subjects receiving different treatments.

experimental group In experimental research, the group of participants given a specific treatment, such as a drug, as part of the study.

control group In experimental research, the group that does not receive the treatment but may be given a placebo instead; used as a standard for comparison.

▶ Figure 1.9 Controlled Scientific Experiments Scientists use experimental research to test hypotheses. Select a large number

of subjects with rickets.

Randomly divide subjects into two groups.

To prevent bias, neither the subjects nor the scientists know which group receives what treatment.

Compare results.

Did the vitamin D cure rickets in the experimental group and did the control group remain unchanged?

Experimental group receives vitamin D supplement.

Control group receives placebo.

Vitamin D cures rickets

Yes No

Revise hypothesis

1

2

3

4

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What Is Credible Nutrition Research? 27

given the experimental group a vitamin D supplement but would have given the control group a placebo, which looked just like the vitamin D supplement but contained only sugar. If neither of the two groups of subjects knew which pill they received, then the subjects were “blind” to the treatment. If the scientists who gave the placebo and the vitamin D supplement also didn’t know which group received which treatment, the exper- iment would be called a double-blind placebo-controlled study. The scientists would also have to make sure that the variables were the same or controlled for both groups during the experiment. For example, they couldn’t let the control group go outside in the sunshine and at the same time keep the experimental group of subjects inside, since sun- light is known to allow humans to synthesize vitamin D. The exposure to the sunshine would change the outcome of the experiment.

A double-blind placebo-controlled study is considered the “gold standard” of research because all of the variables are the same and controlled for the groups of subjects and nei- ther the subjects nor the researcher are biased toward one group.

In any scientific research, sample sizes must be large enough to ensure that differ- ences found in the study are due to the treatment rather than to chance. Studying an entire population is usually impossible because the population is too large, the study would be too expensive or time-consuming, or all members of the population do not want to par- ticipate. This was the case with the vitamin D and rickets study mentioned earlier. It would be virtually impossible to measure all children with rickets. Instead, a sample of children with rickets was used and a statistical comparison was done to estimate the effects on the population. Generally, the larger the sample size, the more confident the researchers are that the data reflects reliable differences that would most likely be seen in the population.

The beauty of science is that one discovery builds on another. Though this may seem frustrating when the findings of one research study contradict the results of another from just a few months before, conflicting findings actually help scientists formulate new ques- tions. Though many hypotheses fail along the way, a great many discoveries are also made.

placebo Inactive substance, such as a sugar pill, administered to a control group during an experiment.

double-blind placebo-controlled study Experimental study in which neither the researchers nor the subjects in the study are aware of who is receiving the treatment or the placebo.

LO 1.8: THE TAKE-HOME MESSAGE Sound nutrition advice is based on years of research using the scientific method. Several methods can be used to con- duct nutrition research, including laboratory experiments on animals, experi- mental research on humans, and observational, particularly epidemiological, research. In double-blind placebo-controlled studies, neither the subjects nor the researchers are aware of who is receiving treatment, and such studies are therefore considered the gold standard of experimental research. Findings from observational and epidemiological research are only considered valid if the study was conducted with an adequate sample size of subjects.

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28 Chapter 1 | What Is Nutrition?

Be careful when taking nutrition advice from a trainer at the gym or the person who works at the local health food store. Whereas some of these people may be credible, many are not, and thus less likely to give you information based on solid scientific evidence. Anyone who calls him- or herself a nutritionist may have taken few or no accredited courses in nutrition.

Beware of Quackery Whereas credible nutrition experts can provide highly useful nutrition guidance, people of questionable credentials often dole out misinformation, usually for the sake of turning a profit. These skilled salespeople specialize in health quackery, or fraud, introducing health fears and then trying to sell services and products to allay these newly created fears. Part of their sales pitch is to make unrealistic promises and guarantees.

To avoid falling for one of their shady schemes, be leery of infomercials, magazine ads, mail-order catalogs, and websites that try to convince you that:

• There is a quick fix for what ails you. • Their product is all natural and mirac-

ulously cures. • One product does it all.

medical nutrition therapy Integration of nutrition counseling and dietary changes, based on individual medical and health needs, to treat a patient’s medical condition.

public health nutritionists Individuals who may have an undergraduate degree in nutrition but who are not registered dietitian nutritionists.

licensed dietitian nutritionist (LDN) Individual who has met specified educational and experience criteria deemed by a state licensing board necessary to be considered an expert in the field of nutrition. An RDN would meet all the qualifications to be an LDN.

nutritionist Generic term with no recognized legal or professional meaning. Some people may call themselves a nutritionist without having any credible training in nutrition.

quackery Promotion and selling of health products and services of questionable validity. A quack is a person who promotes these products and services in order to make money.

How Can You Find and Recognize Credible Nutrition Information? LO 1.9 Explain how to identify reli- able nutrition information and how to recognize misinformation.

If you need legal advice, you seek the expertise of an attorney. If you need knee surgery, you go to an orthopedic surgeon. Where do you go for nutrition advice?

Seek Information from Nutrition Experts Who is a credible expert with training in the field of nutrition? Different health professionals have varying levels of nutrition training, but by far the profes- sional with the most nutrition training is the registered dietitian nutritionist (RDN). An RDN has completed at least a bachelor’s degree from a university or college accredited by the Academy of Nutrition and Dietetics (AND) and has passed the national exam administered by the credentialing body of the AND. The Academy of Nutrition and Dietetics is the largest professional organization in the United States, with a member- ship of over 89,000 nutrition experts. RDNs must maintain registration with the national organization and participate in continuing professional education to remain current in the fast-changing world of nutrition, medicine, and health.

RDNs are trained to administer medical nutrition therapy and work with patients to make dietary changes that can help pre- vent diseases such as heart disease, diabetes, stroke, and obesity. Many physicians, based on the diagnoses of their patients, refer them to RDNs for nutrition advice and guidance. RDNs must participate in con- tinuing professional education in order to remain current in the fast-changing world of nutrition, medicine, and health and to maintain their registration. RDNs work in

hospitals and other health care facilities, private practice, universities, medical schools, professional athletic teams, food companies, and other nutrition-related businesses.

Some individuals other than RDNs, including those with advanced degrees in nutrition, can also provide credible nutrition information. Some physicians and nurses have taken a nutrition course in school and gone on to get a master of science in public health (MPH), which involves some nutri- tion courses, or an MS in nutrition at an accredited university or college.

Some public health nutritionists may have an undergraduate degree in nutrition but didn’t complete a supervised practice so are not eligible to take the AND exam. These individuals can work for state or local governments developing community out- reach nutrition programs, such as programs for older adults.

In order to protect the health of the public, over 40 states currently license nutri- tion professionals. A person who meets these qualifications is a licensed dietitian nutritionist (LDN) and so will have the letters “LDN” after his or her name. Because RDNs have completed the rigor- ous standards set forth by the Academy of Nutrition and Dietetics, they automatically meet the criteria for LDN and often will have both “RDN” and “LDN” after their names.

HEALTHCONNECTION

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HEALTHCONNECTION (CONTINUED)

How Can You Find and Recognize Credible Nutrition Information? 29

• You can lose a lot of weight in a short amount of time and without dieting or exercising.

• The product contains a secret ingredient.

• The product shrinks tumors. • There is no risk, as there is a money-

back guarantee. (Good luck getting your money back!)

Evaluate Nutrition News with a Critical Eye In your lifetime, you will read thousands of newspaper and website headlines, as well as watch and listen to countless television and radio reports announcing sensational head- lines about nutrition. Dramatic headlines are designed to grab your attention, but they can be misleading. Whether they’re delivered via a magazine or newspaper, TV, or online, these headlines should always be considered with a critical eye.

The media are routinely bombarded by press releases sent from medical journals, food companies, organizations, and universi- ties about research being conducted and/ or conferences being sponsored by these institutions. These releases are sent for one reason: to gain publicity. Reputable news organizations that report these findings will seek out independent experts in the field to weigh in on the research and, just as impor- tantly, explain how these findings relate to the public. Even with this added context, there’s often much detail that’s left out of the story. Here are some questions to consider when hearing or reading about a new study, finding, or claim in the mainstream media:

• Was the Research Finding Published in a Peer-Reviewed Journal? You can be more confident that studies published in a peer-reviewed journal have been thoroughly reviewed by experts in this area of research. In most cases, if there are flaws in the study, the study does not get published. If the research isn’t published in a peer-reviewed journal, you have no way of knowing

if the study was conducted in an appropriate manner and whether the findings are accurate. A study about the possible virtues of chocolate in fighting heart disease that is published in the New England Journal of Medicine has more credibility than a similar article published in a baking magazine.

• Was the Study Done Using Animals or Humans? Experiments with animals are often used to study how a particular substance affects a health outcome. But if the study is conducted in rats, it doesn’t necessarily mean that the substance will have the same effect if consumed by humans. This doesn’t mean that animal studies are frivolous; they are important stepping-stones to designing and conducting similar experiments involving humans.

• Do the Study Participants Resemble Me? When you read or hear about studies involving humans, you should always find out more infor- mation about the individuals who took part in the research. For example, were the people in the chocolate studies college-age subjects or older individu- als with heart disease? If older adults were studied, then would these find- ings be of any benefit to young adults who don’t have heart disease?

• Is This the First Time I’ve Heard About This? A single study in a spe- cific area of research is a lonely entity in the scientific world. Is this the first study regarding the health benefits of

chocolate? If the media article doesn’t confirm that other studies have also supported these findings, this one study may be the only study of its kind. Wait until you hear that these research findings have been confirmed by a rep- utable health organization, such as the American Heart Association, before considering making any changes in your diet. Reputable organizations will only change their advice based on a consensus of research findings.

Know How to Evaluate Nutrition Information on the Internet Many people turn to various websites when they have a question about health or nutrition. In fact, approximately 60 percent of American adult Internet users have surfed millions of websites looking for health and medical information.48 Remember that anyone with computer skills can put up a slick website, and many promote misleading or false information.

To help evaluate the validity of websites, the National Institutes of Health (NIH) has developed nine questions to consider:49

1. Who Runs and Pays for the Site? Credible websites are willing to show their credentials. For example, the National Center for Complementary and Integrative Health (www.nccih.nih.gov) provides information about its association

When surfing the Internet for nutrition information, look for a credible, reliable site with up-to-date information.

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30 Chapter 1 | What Is Nutrition?

HEALTHCONNECTION (CONTINUED)

age, and health concerns, which can then be sold to interested companies. Credible sites should state their privacy policy and if they will or will not give or sell this information to other sources.

9. How Does the Site Manage Inter- actions with Visitors? Contact information of the website’s owners should be listed in case readers have any concerns or questions that they want answered. If the site is associ- ated with social media sites such as Twitter or Facebook, you should know how it is moderated. Read the postings before you jump in.

When obtaining information from the Internet, carefully peruse the site to make sure that it is credible and contains up-to-date information and that its con- tent isn’t influenced by those who fund and support the website.

qualified individuals? If the site obtained information from another source, was that source cited?

4. What Is the Basis of the Informa- tion? Is the article’s information based on medical facts and figures that have references? For example, any medical news items released on the American Heart Association website (www.heart.org) will include the medical journal from which the information came. In fact, the web- site will often include the opinion of experts regarding the news item.

5. How Is the Information Reviewed? Check to see if the web- site has an editorial board of medical and health experts and if qualified individuals review or write the con- tent before it is released.

6. How Current Is the Informa- tion? Once a website is on the Internet, it will stay there until some- one removes it. Consequently, the health information that you read may not be the most up to date. Check the date; if it is over a year old, check to see if it has been updated.

7. What Is the Site’s Policy on Link- ing to Other Sites? Some medical sites don’t like to link to other sites, as they don’t have control over other sites’ credibility and content. Others do link, if they are confident that these sites meet their criteria. Don’t assume that the link is credible.

8. How Does the Site Handle Personal Information? Websites track the pages consumers visit to analyze popular topics. Sometimes they elicit personal information such as gender,

with the NIH and its extensive ongoing research and educational programs.

Also, running a website is expen- sive, and finding out who’s paying for a particular site will tell you something about the reliability of its content. Websites sponsored by the government (with URLs ending in .gov), a nonprofit organization (end- ing in .org), or an academic institution (ending in .edu) are more reliable than many commercial websites (ending in .com or .net). Some commercial web- sites, such as WebMD, carry articles that can be reliable if credible health professionals write them, but other websites may be promoting informa- tion to suit a company’s own purposes. For example, if the funding source for the website is a vitamin and min- eral supplement company, are all the articles geared toward supporting the use of supplements? Does the website have advertisers and do their products influence the content of the website?

2. What Is the Purpose of the Site? Look for the “About This Site” link. This will help you understand the website’s purpose. For example, at www.nutrition.gov, the purpose is to “provide easy access to the best food and nutrition information across the federal government.” This website doesn’t exist to sell anything, but to help you find reliable information.

3. Where Does the Information Come From? You should always know who wrote what you are read- ing. Is the author a qualified nutrition expert or did she or he interview

LO 1.9: THE TAKE-HOME MESSAGE Credible nutrition information is obtained from trained nutritional professionals including registered dietitian nutritionists or other valid experts. These professionals have the education and experience to provide reliable nutrition information to achieve an overall healthy diet. Use a critical eye when considering health and nutrition headlines in the media, and be careful when obtaining nutrition information from the Internet. Peruse the website to make sure it is credible, contains up-to-date information, and its content is not influenced by those that fund and support the website.

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Visual Chapter Summary 31

Visual Chapter Summary

LO 1.1 Many Factors Drive Your Food Choices Food choices are influenced by personal taste, culture and environ- ment, social life and trends, nutrition knowledge, advertising, time, convenience, and cost. People often eat out of habit, in response to emotions, and, of course, because food is delicious.

LO 1.2 Nutrition Is the Science of Food Nutrition is the science that studies how the nutrients in food nourish the body, manufac- ture and replace cells, and produce energy. There are six categories of nutrients: carbo- hydrates, lipids, proteins, vitamins, minerals, and water. Carbohydrates, lipids, proteins, and vitamins contain carbon and are classified as organic. Minerals and water are inorganic because they do not contain carbon. Carbo- hydrates and proteins each contain 4 kilocalo- ries per gram, while fats contain 9 kilocalories per gram. Alcohol, though not a nutrient, also contains energy at 7 kilocalories per gram.

Food Choices

Advertising Social reasons

Convenience

Emotions

Time

Habits

Culture

Nutrients

Cost

Taste

TrendsNutrition knowledge

Carbon

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

In or

ga ni

c O

rg an

ic

Hydrogen Oxygen Nitrogen Single elements

Some vitamins contain nitrogen

Carbohydrates

Lipids

Proteins

Vitamins

Minerals

Water

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32 Chapter 1 | What Is Nutrition?

LO 1.4 Eating a Balanced Diet Is the Best Approach to Meeting Your Nutritional Needs A balanced diet that helps prevent chronic diseases includes whole foods and functional foods providing phytochemicals, zoochemicals, and fiber. In some situations, consumption of whole foods and enriched and fortified foods can be combined with dietary supplements for good health.

LO 1.3 Six Nutrient Groups Have Primary Roles in the Body Carbohydrates, fats (lipids), and proteins provide energy in the form of kilocalories. Carbohydrates are the body’s preferred source of energy. Fats insulate the body and cushion internal organs. The primary role of dietary protein is to build and maintain body tissues. Proteins also act as enzymes that catalyze chemical reactions. Vitamins and minerals do not provide energy but are necessary to properly metabolize carbohydrates, fats, and protein. Many vitamins aid enzymes in the body. Water bathes the inside and outside of the cells, helps maintain body temperature, acts as a lubricant and protective cushion, and delivers nutrients and oxygen to the cells.

LO 1.5 A Healthy Diet Can Reduce the Risk of Chronic Disease, Prevent Deficiency Disease, and Enhance Gene Expression A healthy diet plays an important role in reducing the risk for many of the leading causes of death in the United States, including heart disease, cancer, stroke, and type 2 diabetes. It also prevents nutrient-deficiency diseases such as scurvy and iron-deficiency anemia. Interactions between nutrition and dis- ease are explored in the science of nutritional genomics, which studies the relationship between genes, gene expression, and nutrition.

Environmental influences Diet

Physical activity

Gene variants Susceptibility genes

Chronic Disease

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Visual Chapter Summary 33

a

b

LO 1.6 We Assess Nutritional Status Using the ABCD Method The ABCD methods for assessing an individual’s nutri- tional status include—after taking the health history— collecting anthropometric and biochemical laboratory data, clinical observation, and conducting dietary intake surveys. The nutritional status of population groups is determined by national surveys and studies, including the National Health and Nutrition Examination Survey and the Framingham Heart Study.

LO 1.7 The Average American Diet Needs Improvement Most Americans are not meeting all their nutrient needs without exceeding their kilocalorie requirements. The average American diet is high in added sugars, sodium, and saturated fat, but low in vitamin D, calcium, potassium, and fiber. In addition, the rates of overweight and obesity among Americans are too high.

Hypothesis supported

Publish findings

Develop theory

Establish consensus

LO 1.8 The Scientific Method of Research Provides Credible Nutrition Information Sound nutrition information is the result of numerous scientific studies conducted according to the scientific method, which includes observing, formulating a hypoth- esis, and conducting one or more experiments. Studies are reviewed by the medi- cal and scientific community. Nutrition research is conducted through laboratory experiments, experimental research, and observational and epidemiological studies. Findings are presented in peer-reviewed journals.

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34 Chapter 1 | What Is Nutrition?

LO 1.9 Reliable Nutrition Information Comes from Authoritative Sources Nutrition advice should come from credible sources including registered dietitian nutritionists who have the education and training to provide reliable and accurate information. Individuals who call themselves nutritionists may or may not have a credible nutrition education. Use critical thinking to evaluate media headlines and product claims relating to health and nutrition. When looking for nutrition and health information on the Internet, seek out the sites of credible organizations that provide up-to-date information from reliable sources.

Terms to Know ■■ nutrition ■■ nutrients ■■ essential nutrients ■■ nonessential nutrients ■■ organic ■■ inorganic ■■ energy ■■ energy-yielding nutrients ■■ kilocalorie ■■ macronutrients ■■ micronutrients ■■ enzymes ■■ coenzymes ■■ solubility ■■ water-soluble vitamins ■■ fat-soluble vitamins

■■ major minerals ■■ trace minerals ■■ functional foods ■■ phytochemicals ■■ zoochemicals ■■ chronic disease ■■ gene expression ■■ epigenetics ■■ nutritional genomics ■■ registered dietitian nutritionist (RDN) ■■ malnourished ■■ undernourished ■■ overnourished ■■ acute ■■ malabsorption ■■ body mass index (BMI) ■■ added sugars

■■ consensus ■■ scientific method ■■ hypothesis ■■ peer-reviewed journal ■■ laboratory experiment ■■ observational research ■■ epidemiological research ■■ experimental research ■■ experimental group ■■ control group ■■ placebo ■■ double-blind placebo-controlled study ■■ medical nutrition therapy ■■ public health nutritionists ■■ licensed dietitian nutritionist (LDN) ■■ nutritionist ■■ quackery

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Answers 35

Mastering Nutrition Visit the Study Area in Mastering Nutrition to hear an MP3 chapter summary.

Check Your Understanding LO1.1 1. Megan picks up a sandwich

at the campus food truck after class every day before dashing off to her part-time job. Which of the following most likely drives Megan’s food choice? a. her ethnic background b. her busy schedule c. her emotions d. her limited budget

LO1.2 2. Nutrition is a. the study of genes, how they

function in the body, and the environment.

b. the study of how the body functions.

c. the study of nutrients and other components of foods and their effect on body functions and health.

d. the study of hormones and how they function in the body.

LO1.2 3. Minerals are considered an organic nutrient because they contain the element carbon. a. True b. False

LO1.2 4. A slice of whole-wheat bread contains 1 gram of fat, 18 grams of carbohydrate, and 4 grams of protein. How many kilocalories does it contain? a. 65 kilocalories b. 72 kilocalories c. 89 kilocalories d. 97 kilocalories

LO1.3 5. Which of the following roles do nutrients perform in the body? a. Nutrients provide energy. b. Nutrients provide structure

for bone, muscle, and other tissues.

c. Nutrients facilitate metabolism.

d. Nutrients perform all of the above functions.

LO1.4 6. Dietary supplements are neces- sary to meet your nutrient needs. a. True b. False

LO1.5 7. Which of the following state- ments about diet and health is true? a. The top five causes of death

in the United States are all related to nutrition.

b. Nutritional genomics is the study of how the foods we eat alter the structure of our DNA.

c. Components of the foods we eat can alter the expression of our genes as proteins.

d. Cancer is an example of a nutrient-deficiency disease.

LO1.6 8. Which of the ABCD assess- ments yields data about body weight and body composition? a. Anthropometric b. Biochemical c. Clinical d. Dietary intake

LO1.7 9. The current state of the American diet is reflected in the fact that more than ______________ percent of American adults are obese. a. 35 b. 45 c. 55 d. 65

LO1.8 10. The first step in the scientific method is to a. make observations and ask

questions. b. form a hypothesis. c. conduct an experiment. d. develop a theory.

Answers 1. (b) While food choices are influ-

enced by many factors, including eth- nic background, emotions, and costs, in Megan’s case her limited time for food preparation and/or shopping most strongly influences her choice of this fast-food sandwich.

2. (c) Nutrition is the science related to how nutrients and other components in foods are used in the body and

how they affect health. The study of genes is called genetics. Physiology is the study of how the body functions. The study of hormones is called endocrinology.

3. (b) Minerals are actually inorganic nutrients because they do not contain carbon. Nutrients that do contain carbon, including protein, carbohydrates, lipids, and vitamins, are classified as organic.

4. (d) A slice of bread contains 97 kilocalories: (18 g * 4 kcal) + (4 g * 4 kcal) + (1 g * 9 kcal).

5. (d) Nutrients help perform numerous vital body functions. Carbohydrates, protein, and fats provide energy in the form of kilocalories; protein and some min- erals help build body tissues; and several vitamins and minerals are essential during metabolic processes.

6. (b) False. Dietary supplements can be beneficial for individuals with diet restrictions or higher nutrient needs, but they are not essential. Consum- ing a diet rich in a variety of whole foods is the best way to achieve a healthy, balanced diet.

7. (c) Components of the foods we eat can alter the expression of our genes as proteins. Nutritional genomics studies these and other links between genetics and diet. The foods we eat do not, however, alter the structure of our DNA. Three of the top five causes of death in the United States—not all five—are related to nutrition. Cancer is a multifactorial disease in which nutrition may play a role, but cancer is not caused by a nutrient deficiency.

8. (a) Anthropometric measurements yield data about body weight and body composition. Biochemical measurements are tests of blood, urine, and feces, and clinical tools are observations of your hair, skin, muscles, and overall appearance to assess for signs of deficiencies or excess nutrients. Dietary intake records diet history or uses a survey, food frequency questionnaire, or diet record to assess nutrient intake.

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36 Chapter 1 | What Is Nutrition?

9. (a) Over 35 percent of American adults are considered obese.

10. (a) The scientific method begins with scientists observing and ask- ing questions. They then formulate a hypothesis and test it using an experiment to confirm their hypoth- esis. After many experiments that confirm their hypothesis, a theory is developed.

Answers to True or False? 1. True. Taste is the strongest moti-

vating factor for choosing foods. However, numerous other fac- tors—including culture, social setting, health, advertising, habit, emotion, time, cost, and conve- nience—also play a role in food choice.

2. False. Nutrition is the science related to how nutrients are used in the body and how they affect health.

3. True. Carbohydrates are the primary source of energy to the body.

4. False. Whereas alcohol does provide kilocalories, eliminating it from the diet would not result in malnutri- tion. Therefore, alcohol is not a nutrient.

5. False. There is no replacement for whole foods in a healthy diet. A sup- plement can augment a healthy diet, but it can’t replace it to meet your nutritional needs.

6. False. The 24-hour diet record is one tool for gathering information about the quality of a client’s diet, but it doesn’t reveal a complete picture. Long-term food records, interviews, and anthropometric data are also needed.

7. False. In 2015, more than 35 percent of American adults were considered obese.

8. False. Eliminating all fat from the diet is incompatible with life. In the short term, it would result in nutrient deficiencies and do little to reduce your risk of heart disease. Chronic disease such as heart disease is often the result of a cluster of risk factors including an overall poor-quality diet, lack of exercise, and tobacco use, as well as heredity.

9. False. Heart disease is the leading cause of death among Americans. The good news is that your diet can play an important role in reducing your risk.

10. False. There is no standard for or legal definition of the word nutritionist, so it does not convey expert status. In fact, anyone can call him- or herself a nutritionist.

Web Resources Examples of reliable nutrition and health websites include:

■■ Academy of Nutrition and Dietetics: www.eatright.org

■■ Agricultural Research Service: www .ars.usda.gov

■■ American Cancer Society: www.cancer .org

■■ American College of Sports Medicine: www.acsm.org

■■ American Medical Association: www .ama-assn.org

■■ Center for Science in the Public Inter- est: www.cspinet.org

■■ Centers for Disease Control and Pre- vention: www.cdc.gov

■■ Food and Drug Administration: www .fda.gov

■■ Food and Nutrition Information Cen- ter: www.nal.usda.gov/fnic

■■ National Institutes of Health: www .nih.gov

■■ NHANES Surveys: www.cdc.gov/ nchs/nhanes.htm

■■ Nutrition.gov: www.nutrition.gov ■■ Shape Up America!: www.shapeup.org ■■ Vegetarian Resource Group: www.vrg

.org

References 1. Van Meer, F., Charbonnier, L., and Smeets,

P. 2016. Food Decision-Making: Effects of Weight Status and Age. Current Diabetes Reports 16:2–8.

2. Freeland-Graves, J., and S. Nitzke. 2013. Position Paper of the Academy of Nutri- tion and Dietetics: Total Diet Approach to Healthy Eating. Journal of the Academy of Nutrition and Dietetics 113:307–317.

3. Food Information Council Foundation. 2016. Food Decisions 2016. Available at http://www.foodinsight.org/articles/ 2016-food-and-health-survey-food-decision -2016-impact-growing-national-food -dialogue. Accessed January 2017.

4. Freeland-Graves, J. 2013.

5. Freeland-Graves, J. 2013. 6. Shen, Y., O. Kennedy, and L. Methven. 2017.

The Effect of Genotypical and Phenotypical Variation In Taste Sensitivity on Liking of Ice Cream and Dietary Fat Intake. Food Qual- ity and Preference 55:79–90.

7. Ambrosini, G., D. Johns, K. Northstone, P. Emmetee, and S. Jebb. 2016. Free Sugars and Total Fat Are Important Characteristics of a Dietary Pattern Associated with Adiposity Across Childhood and Adolescence. Journal of Nutrition 146:778–784.

8. Drewnowski, A. 1997. Taste Preferences and Food Intake. Annual Review of Nutrition 17:237–253.

9. Ambrosini, G., 2016. 10. Van Meer, F., 2016. 11. Wansink, B., C. R. Payne, and M. Shimizu.

2010. “Is This a Meal or Snack?”: Situ- ational Cues that Drive Perceptions. Appetite 54:214–216.

12. National Turkey Foundation. 2016. Turkey Facts and Trivia. Available at www.eatturkey .com. Accessed January 2017.

13. Freeland-Graves, J. 2013. 14. National Restaurant Association. 2011. Pizza

Is King of Super Bowl Takeout. Available at www.restaurant.org. Accessed January 2017.

15. Udland, M. 2015. Here’s How Movie The- aters are Still Making Money Even Though Ticket Sales are Down. Business Insider. Avail- able at www.businessinsider.com/movie -concessions-drive-amc-earnings-2015-2. Accessed January 2017.

16. Organic Trade Association. 2015. Quick Stats. Available at www.ota.com. Accessed January 2017.

17. Food Information Council Foundation. 2016. Food Decisions 2016.

18. Ibid. 19. Ibid. 20. Statista. 2016. Statistics and Facts About

Food Advertising. Available at https://www .statista.com/topics/2223/food-advertising/. Accessed January 2017.

21. Vilaro, M., T. Barnett, A. Watson, J. Merten, and A. Mathews. 2017. Weekday and Week- end Food Advertising Varies on Children’s Television in the USA but Persuasive Tech- niques and Unhealthy Items Still Dominate. Public Health 142:22–30.

22. Blake, JS. 2016. Celebrity Watching in the Produce Aisle. Available at http:// salge-blake.blogspot.com/2016/07/ celebrity-watching-in-produce-aisle.html. Accessed January 2017.

23. International Food Information Council (IFIC) Foundation’s 2015 Food and Health Survey: the Millennials. 2015. Available at www.foodinsight.org/2015-food-health -survey-millennial-research. Accessed January 2017.

24. Specialty Coffee Association. 2015. US Coffee Shops. Available at www.scaa.org. Accessed January 2017.

25. U.S. Department of Agriculture. 2016. Food Expenditures. Available at www.ers.usda.gov. Accessed January 2017.

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References 37

26. Burgoine, T., N. Forouhi, S. Griffin, S. Brage, N. Wareham, and P. Monsivatis. 2016. Does Neighborhood Fast-Food Outlet Exposure Amplify Inequalities in Diet and Obesity?: A Cross-Sectional Study. American Journal of Clinical Nutrition 103:1540–1547.

27. Mintel International Group. 2016. Cooking Enthusiasts. Available at www.mintel.com/. Accessed January 2017.

28. Sy, S., J. Penalvo, S. Abrahams-Gessel, S., Alam, A. Pandya, D. Mozaffarian, and T. Gaziano. 2016. Changes in Food Prices Improve Cardiovascular Disease (CVD) Outcomes. Circulation 133:AP280.

29. Mintel International Group. 2016. What’s for Breakfast? Available at www.mintel.com. Accessed January 2017.

30. Maddison, R., L. Foley, C. N. Mhurchu, Y. Jiang, A. Jull, H. Prapavessis, M. Hohepa, and A. Rodgers. 2011. Effects of Active Video Games on Body Composition: A Ran- domized Controlled Trial. American Journal of Clinical Nutrition 94:156–163.

31. Crowe, K, and C. Francis. 2013. Position of the Academy of Nutrition and Dietetics: Functional Foods. Journal of the Academy of Nutrition and Dietetics 113:1096–1103.

32. Bolarin, D., E. Ekpe, K. Saidu, and E. Eyam. 2016. Overview of Foods with Antioxidant Effects-Clinical Relevance. European Journal of Food Science and Technology 4:1–9.

33. Crowe, K. 2013. 34. Forster, H, M. Walsh, M. Givney, L.

Brennan, and E. Gibney. 2016. Person- alised Nutrition: The Role of New Dietary

Assessment Methods. Proceedings of the Nutri- tion Society 75:96–105.

35. Eaton, D. K., E. O. Olsen, N. D. Brener, K. S. Scanlon, S. A. Kim, Z. Demissie, and A. L. Yaroch. 2013. A Comparison of Fruit and Vegetable Intake Estimates from Three Survey Question Sets to Estimates from 24-Hour Dietary Recall Interviews. Journal of the Academy of Nutrition and Dietetics 113(9):1165–1174.

36. Illner, A-K., H. Freisling, H. Boeing, I. Huy- brechts, S. P. Crispim, and N. Slimani. 2012. Review and Evaluation of Innovative Tech- nologies for Measuring Diet in Nutritional Epidemiology. International Journal of Epidemi- ology 41(4):1187–1203.

37. U.S. Department of Agriculture, Agricul- tural Research Service. 2016. What We Eat in America, NHANES 2013-2014. Available at https://www.ars.usda.gov/northeast-area/ beltsville-md/beltsville-human-nutrition -research-center/food-surveys-research -group/docs/wweianhanes-overview/. Accessed January 2017.

38. U.S. Department of Health and Human Ser- vices and U.S. Department of Agriculture. 2015. 2015–2020 Dietary Guidelines for Ameri- cans. 8th Edition. Available at http://health. gov/dietaryguidelines/2015/guidelines/.

39. U.S. Department of Agriculture, Agricultural Research Service. 2016.

40. U.S. Department of Agriculture, Agricul- tural Research Service. 2016. What We Eat in America, NHANES 2013–2014. Available at https://www.ars.usda.gov/northeast-area

/beltsville-md/beltsville-human-nutrition -research-center/food-surveys-research -group/docs/wweianhanes-overview/. Accessed January 2017.

41. Ibid. 42. Kantor, E., C. Rehm, M. Du., E. White, and

E. Giovannucci. 2016. Trends in Dietary Supplement Use Among US Adults from 1999–2012. Journal of the American Medical Association 316:1464–1471.

43. U.S. Department of Agriculture. 2016. 44. Golden, N., M. Schneider, and C. Wood.

2016. Preventing Obesity and Eat- ing Disorders in Adolescents. Pediatrics 138(3):e20161649.

45. Buckner, S., P. Loprinzi, and J. Loenneke. 2016. Why Don’t More People Eat Break- fast?: A Biological Perspective. American Jour- nal of Clinical Nutrition 103:1555–1559.

46. Centers for Disease Control. 2016. Adult Obesity Facts. Available at www.cdc.gov. Accessed January 2017.

47. U.S. Department of Health and Preventa- tive Services. Updated 2017. Healthy People 2020. Available at www.healthypeople.gov. Accessed January 2017.

48. Fox, S., and M. Duggan. 2013. Health Online 2013. Pew Research Center’s Internet and Ameri- can Life Project. Available at www.pewinternet .org. Accessed January 2017.

49. National Center for Complementary and Integrative Health Medicine. Updated 2014. Online Health Information: Can You Trust It? Available at https://nccih.nih.gov/ health/webresources. Accessed January 2017.

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39

2 Learning Outcomes After reading this chapter, you will be able to:

2.1 Describe the key principles of healthy eating.

2.2 Distinguish between the Dietary Reference Intake terms EAR, AI, RDA, UL, and AMDR.

2.3 Describe the recommendations included in the Dietary Guidelines for Americans.

2.4 Discuss the concept of MyPlate, including the food groups and typical foods represented.

2.5 Explain how the exchange system can be used as a guide to plan a balanced diet.

2.6 Identify the required components of a food label and Nutrition Facts panel.

2.7 Compare the terms portion and serving size and summarize the health benefits of control- ling your portions.

True or False? 1. Having a balanced diet means eating the same number of servings from each food group. T/F

2. There isn’t any risk in overconsuming the essential nutrients in your diet. T/F 3. The current Dietary Reference Intakes for vitamins and minerals are set at the amount you should consume daily to maintain good health. T/F

4. If you follow the advice in the Dietary Guidelines for Americans, you can reduce your risk of dying from chronic diseases such as heart disease and dia-betes mellitus. T/F

5. According to the USDA MyPlate food guide, there are five basic food groups. T/F

6. Healthy oils are a food group in MyPlate. T/F

7. Exchange lists are similar to MyPlate except the foods are based on the car-bohydrate, protein, fat, and kilocalorie contents. T/F 8. A nutrient content claim on a food label tells you why that nutrient is good for you. T/F 9. All packaged foods must contain a food label. T/F

10. A portion of food is defined as a stan-dard serving size. T/F See  page 71 for the answers.

Tools for Healthy Eating

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40 Chapter 2 | Tools for Healthy Eating

What Are the Key Principles of Healthy Eating? LO 2.1 Describe the key principles of healthy eating.

Healthy eating means you need to balance, vary, and moderate your nutrient intake. In addition, a healthy diet includes foods that are high in nutrient density and low in energy density.

Healthy Eating Means Balance between Food Groups A balanced diet includes healthy proportions of all nutrients and is adequate in energy. A diet that lacks balance can cause undernutrition. For instance, a student subsisting largely on bread, bagels, muffins, crackers, chips, and cookies might be eating too much carbohydrate and fat but too little protein, vitamins, and minerals. If the diet lacks a par- ticular nutrient, such as protein, over time the body suffers from malnutrition. A meal that contains foods from the grain, vegetable, fruit, meat, and dairy groups, such as a lunch of a turkey-and-cheese wrap with lettuce and tomato plus an apple, provides the proper proportion of foods from each of the food groups. This balancing act prevents overnutrition of a specific nutrient, such as fat,1 or too many kilocalories, which can lead to overweight and obesity. Consuming adequate amounts of all essential nutrients is key to avoiding nutrient deficiencies and, in many cases, chronic disease.

balance Diet principle of providing the correct proportion of nutrients to maintain health and prevent disease.

vary Diet principle of consuming a mixture of different food groups and foods within each group.

moderate Diet principle of providing reason- able but not excessive amounts of foods and nutrients.

nutrient density Measurement of the nutri- ents in a food compared with the kilocalorie content; nutrient-dense foods are high in nutri- ents and low in kilocalories.

energy density Measurement of the kilo- calories in a food compared with the weight (grams) of the food.

A meal that contains foods from every food group is part of a bal- anced, healthy diet.

Many Americans believe that to eat a healthful diet means giving up their favorite foods. Nothing could be farther from the truth! With a little planning, you can still occasionally eat almost any food even if it contains added sugars and fat and is high in kilocalories. All it takes are the right tools to

balance those higher kilocalorie foods with more nutritious choices each day.

The good news is that a number of tools are available to help you achieve a healthful, balanced eat-

ing plan. This chapter explains how to use these tools in a consistent manner that over time will lead to

better eating habits. Let’s begin with a discussion of what healthy eating is.

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What Are the Key Principles of Healthy Eating? 41

Healthy Eating Means Consuming a Variety of Foods Choosing a variety of foods improves the quality of the diet because the more var- ied the food choices, the better the chance of consuming adequate amounts of all the essential nutrients.2 Even within one food group, the nutrient composition of foods can vary dramatically. For example, while broccoli is a good source of folate, it has less than half the vitamin A of a carrot. Similarly, if the only fruit you eat is bananas, your diet would include an excellent source of potassium, but could be low in vitamin C. Because no single food or food group contains everything you need to be healthy, you should choose a variety of foods from within each food group and among food groups each day. This is the basic principle of the Fruits & Veggies—More Matters campaign developed by the Produce for Better Health Foundation and the Centers for Disease Control and Prevention.3 This campaign promotes eating a vari- ety of colorful fruits and vegetables—which are rich in vitamins, minerals, fiber, and phytochemicals—each day to help reduce the risk of cancer and heart disease and slow the effects of aging.

Healthy Eating Means Moderate Intake of All Foods According to many registered dietitian nutritionists (RDNs), “there are no good or bad foods, just good or bad habits.” What they mean is that all foods—even less nutritious foods—can be part of a healthy diet, as long as they are consumed in moderation. Foods such as sweets and fried or packaged snack foods should be eaten only in small amounts to avoid consuming too much sugar and saturated fat, as well as too many kilocalories. Finally, these foods can displace more nutritious choices, resulting in a diet that lacks essential nutrients. Even some healthy foods, such as nutrient-dense nuts, can be high in kilocalories and should be consumed in moderation. Healthy eating doesn’t mean you can’t enjoy your favorite foods. It simply means eating those foods in moderation by lim- iting the portion size and number of servings you eat.

Many people overestimate the appropriate portion sizes of foods. An entire body of research is devoted to studying factors that affect how much we put on our plates. The important point is that, in general, we tend to consume portions larger than necessary to meet our kilocalorie needs. See the Health Connection on pages 65–67 for examples of visuals you can use to estimate portion sizes. For suggestions on eating a balanced, varied, and moderate diet, see the Table Tips.

Healthy Eating Includes Nutrient-Dense Foods Healthy eating also means choosing foods that are nutrient dense. Nutrient-dense foods are high in nutrients, such as vitamins and minerals, but low in energy (kilocalories), pro- viding more nutrients per kilocalorie (and in each bite) than less nutrient-dense foods.4 Fresh fruits and vegetables, for example, are nutrient dense because they are high in B vitamins, vitamin C, and minerals such as calcium and magnesium, as well as dietary fiber, while usually providing fewer than 60 kilocalories per serving.

Nutrient-dense foods are also low in saturated fat and added sugars. To illustrate this concept, compare the nutrient density of two versions of the same food: a baked potato and potato chips (Figure 2.1). Although a medium baked potato and one ounce of potato chips have about the same number of kilocalories, the baked potato provides much higher amounts of vitamins and minerals than the deep-fried chips.

Though many foods, such as vegetables, are clearly nutrient dense, and other foods, such as candy, are clearly not, some foods do not fit neatly into these two categories. Items such as dried fruits, nuts, peanut butter, and avocados are higher in kilocalories, but they are also excellent sources of important nutrients, including polyunsaturated fatty acids, calcium, and iron. Other foods, such as whole milk or yogurt, are higher

portion Quantity of a food usually eaten at one sitting.

Choosing a variety of nutrient-dense foods you enjoy is a key to eating a healthy diet.

TABLE TIPS

Tips for a Balanced, Varied, and Moderate Diet

Keep healthy snacks such as whole- grain crackers in your dorm room and combine them with protein-rich peanut butter or low-fat yogurt.

Pop a snack-pack size of light micro- wave popcorn for a portion-controlled whole-grain snack while you study.

Adopt a multicolor code to guide your food choices. Add tomato slices and a low-fat cheese slice to your whole-grain sandwich and carrots to your tossed green salad to ensure that your choices are adequate and varied.

Pack your own snack-sized portions of dried fruit, trail mix, whole-wheat crack- ers, baby carrots, or salt-free pretzels to carry in your backpack. Snack-sized bags of nuts and seeds are a nutri- tious way to help you avoid the vending machine and eat smaller, more moder- ate portions.

Keep your sweets to no more than about 100 kilocalories a day.

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42 Chapter 2 | Tools for Healthy Eating

in saturated fat and kilocalories than their nonfat or low-fat counterparts, but still pro- vide significant amounts of calcium, riboflavin, vitamins A and D, and protein. Some foods, such as fruit-flavored yogurt and some fortified cereals, contain added sugars in addition to several essential nutrients. Do you think these foods can be considered nutrient dense?

In all of these scenarios, the answer is yes. Whereas nutrient dense usually means high in nutrients and low in energy, foods that are high in nutrients and high in energy can also be considered nutrient dense. The key is to be aware of the extra kilocalories and make up for them elsewhere in the diet. If you don’t like skim milk and won’t drink it, but do enjoy the taste of whole milk, then drinking whole milk is a more healthy choice than drinking soda.

Healthy Eating Includes Low-Energy-Dense Foods In contrast to nutrient density, energy density refers to foods that are high in energy but low in weight or volume, such as that potato chip. A serving of deep-fried chips weighs much less than a plain baked potato, but is considerably higher in kilocalories. Therefore, the chip contains more energy per gram. A big, leafy green salad, on the other hand, is large in volume but low in energy density, because of its high water content.

Most high-fat foods are considered energy dense.5 This is because fat has 9 kilocalories per gram and is thus 2.25 times more energy dense than either carbohy- drates or protein at 4 kilocalories per gram. Individuals who choose low-energy-dense foods will generally have diets that are lower in fat and higher in nutrient content.

Eating a low-energy-dense diet can sometimes be the key to weight loss. Recent studies have found that leaner individuals ate more low-energy-dense foods and fewer kilocalories, while consuming a greater volume of food, compared with their obese counterparts.6 Even modest changes in dietary intake may promote and help maintain weight loss7 over time.8 One reason for this may be that eating higher-volume, lower- energy foods means larger portions for the same number of kilocalories. Other reasons may include improved satiety and appetite control.9 In other words, low-energy foods will “fill you up before they fill you out.”

If you are trying to maintain your current weight, or lose weight, you are probably on a limited energy budget and need to choose foods that are nutrient dense and low in kilocalories. Use the guide in Table 2.1 to help stretch your energy budget while con- suming the most nutrient-dense foods.

satiety Feeling of satiation, or “fullness,” after a meal before hunger sets in again.

▲ Figure 2.1 Which Is the Healthier Way to Enjoy Potatoes? Whereas one ounce of potato chips and one medium baked potato have similar kilocalories, their nutrient content is worlds apart. A baked potato contains more folate, potassium, and vitamin C, and fewer fat kilocalories, than its fried counterpart. The baked potato is therefore more nutrient dense than potato chips. * Note: Based on the percentage of the DRI for 19- to -50-year-old males. All these percentages apply to females in the same age range, except for vitamin C. Females have lower vitamin C needs than males, so a baked potato provides over 20 percent of the DRI of this vitamin for women.

100

0

20

40

60

80

Pe rc

en t D

R I*

Potato chips, 1 oz

Baked potato, medium

Vitamin CPotassiumFolate

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What Are the Key Principles of Healthy Eating? 43

Many Resources Are Available for Planning a Healthy Diet Do you think all this advice for planning a healthy diet is hard to keep straight? If so, you’re not alone. Fortunately, several tools can help you avoid both under- and overnutri- tion, including:

• The Dietary Reference Intakes (DRIs), which provide recommendations regarding your nutrient needs

• The Dietary Guidelines for Americans, which provide broad dietary and lifestyle advice • MyPlate, part of the ChooseMyPlate.gov Web-based initiative, which is designed

to help you eat healthfully and implement the recommendations in the DRIs and the advice in the Dietary Guidelines

• The exchange system, which groups foods according to their macronutrient content, thus making it easier to plan meals

• The Nutrition Facts panel on food labels, which contains the percent Daily Values, and which can help you decide which foods to buy

Together, these tools help you plan a balanced, moderate, and varied diet that meets your nutrient and health needs. Table 2.2 compares these tools, and the following text sec- tions discuss each in more detail.

Foods Energy Density Are They an Energy Bargain?

Soups Fruits Vegetables

0.0–0.6 kcal/g Great Energy Bargain: Eat as much of these low-energy-density foods as you want; however, take care that soups don’t contain too much sodium and are made with broth rather than cream.

Starchy fruits and vegetables Lean meats Beans and legumes

0.6–1.5 kcal/g Good Energy Bargain: Consume healthy portions of these foods.

Cheese Salad dressings Snack foods

1.5–4.0 kcal/g More Expensive Choices: These foods should be chosen carefully and con- sumed in moderation.

Chocolates Chips Candy Deep-fat fried foods Desserts

4.0–9.0 kcal/g Very Expensive Choices: Eat less of these foods and be aware of the portion size to avoid overconsuming kilocalories.

Source: Adapted from B. Rolls. 2012. The Ultimate Volumetrics Diet: Smart, Simple, Science-Based Strategies for Losing Weight and Keeping It Off. New York: HarperCollins.

TABLE 2.1 Bargain Shopping on an Energy Budget

DRIs Dietary Guidelines for Americans MyPlate

Nutrition Facts Panel

Exchange Lists for Healthy Eating

What Are They?

Specific reference values for each nutrient by age and gender.

Guidelines for nutri- tion and health that are informed by the most cur- rent scientific evidence, updated every 5 years.

A representational icon that depicts five food groups using the familiar mealtime visual of a place setting.

Contains impor- tant nutrition infor- mation to be used to compare food products.

Lists that are orga- nized into food groups by their carbohydrate, protein, fat, and kilo- calorie contents.

How Do They Guide You in Healthy Eating?

DRIs provide rec- ommendations to prevent malnutrition and chronic diseases for each nutrient. The upper level is designed to prevent overnutri- tion or toxicity.

The Dietary Guidelines emphasize following a healthy, plant-based diet to maintain a healthy weight and reduce the risk for chronic disease.

MyPlate is the focal point for the Web-based ChooseMyPlate.gov initiative, which provides information to build a healthy diet based on the Dietary Guidelines for Americans.

You can use the Nutrition Facts panel to compare the nutrient den- sity of foods.

It’s easy to plan healthy menus with a variety of foods. The exchanges are based on specific food por- tion sizes plus various fat levels in foods.

TABLE 2.2 Putting It All Together: Tools for Healthy Eating

(continued)

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44 Chapter 2 | Tools for Healthy Eating

LO 2.1: THE TAKE-HOME MESSAGE Healthy eating emphasizes con- suming the right amount of food from a variety of food groups to provide an adequate intake of nutrients and a moderate level of energy. Choosing nutrient- dense and low-energy-dense foods ensures a diet high in nutrient content and low enough in energy to prevent weight gain. A variety of tools are available to help individuals make healthy choices.

What Are the Dietary Reference Intakes? LO 2.2 Distinguish between the Dietary Reference Intake terms EAR, AI,

RDA, UL, and AMDR.

The Dietary Reference Intakes (DRIs) are issued by the Food and Nutrition Board (FNB) of the National Academy of Medicine. They identify the amounts of each nutrient that people in a specific life stage need to consume to maintain good health, prevent chronic diseases, and avoid unhealthy excesses.10 The recommendations are grouped according to life stage—such as childhood, older age, or pregnancy—because nutrient requirements differ according to these stages. A teenager may need more of a specific nutrient than a 55-year-old (and vice versa) and women need more of certain nutrients during pregnancy and lactation. Many of the recommendations also differ by gender. Males and females vary in some of their nutrient requirements because of differ- ences in their anatomy and physiology.11

The National Academy of Medicine periodically organizes committees of U.S. and Canadian scientists and health experts to update the DRIs to reflect the latest scientific research. Since the 1940s, the DRIs have been updated 10 times. In the 1990s, nutrition researchers identified expanded roles for many nutrients. Though nutrient deficiencies were still an important issue, research suggested that higher amounts of some nutrients could play a role in disease prevention. Also, as consumers began using more dietary sup- plements and fortified foods, committee members grew concerned that excessive con- sumption of some nutrients might be as unhealthy as, or even more dangerous than, not consuming enough. Hence, the FNB convened a variety of committees between 1997 and 2004 to take on the enormous task of reviewing the research on vitamins, minerals, carbohydrates, fats, protein, water, and other substances such as fiber and developing the current DRI reference values. The DRIs are continually updated as research evolves.

Dietary Reference Intakes (DRIs) Refer- ence values for nutrients developed by the Food and Nutrition Board of the National Academy of Medicine, used to plan and evaluate the diets of healthy people in the United States and Canada. It includes the Estimated Average Requirement (EAR), the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), and the Tolerable Upper Intake Level (UL).

nutrient requirements Amounts of specific nutrients needed to prevent malnutrition or deficiency; reflected in the DRIs.

DRIs Dietary Guidelines for Americans MyPlate

Nutrition Facts Panel

Exchange Lists for Healthy Eating

What Are They Made Up Of?

EARs, RDAs, AIs, ULs, and AMDRs

Key messages emphasize healthy eating patterns, as well as limiting intake of added sugars, satu- rated fats, sodium, cho- lesterol, and caffeine.

Recommendations are made for physical activ- ity as well as five food groups, plus oils:

1. Vegetables 2. Fruits 3. Grains 4. Protein 5. Dairy 6. Oils

Information is pre- sented about:

• Serving size, servings per package, and kilocalories per serving

• Macronutrients • Dietary fiber • Vitamins and

minerals • % Daily Values

Exchange lists consist of six food groups:

1. Starch 2. Meat 3. Vegetables 4. Fruit 5. Milk 6. Fat

TABLE 2.2 Putting It All Together: Tools for Healthy Eating (continued)

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What Are the Dietary Reference Intakes? 45

The DRIs Encompass Several Reference Values The DRIs cover five reference values: the Estimated Average Requirement (EAR), the Recommended Dietary Allowance (RDA), the Adequate Intake (AI), the Tolerable Upper Intake Level (UL), and the Acceptable Macronutrient Distribution Range (AMDR) (Focus Figure 2.2 ). Each of these values is unique, and serves a different need in plan- ning a healthy diet.

Estimated Average Requirements The DRI committee members begin by reviewing a variety of research studies to deter- mine the Estimated Average Requirement (EAR) for a nutrient. They may look at studies that investigate the consequences of eating a diet too low in the nutrient and the associated side effects or physical changes that develop, as well as how much of the nutrient should be consumed to correct the deficiency. They may also review studies that measure the amount a healthy individual absorbs, stores, and maintains daily. Addition- ally, they look at research studies that address the role the nutrient plays in reducing the risk of associated chronic diseases, such as heart disease. After a thorough review pro- cess, the EAR for the nutrient is determined.

The EAR is the average amount of a nutrient projected to meet the needs of 50  percent of healthy Americans by age and gender.12 The EAR is a good starting point to determine the amount of a nutrient an individual should consume daily for good health. As you can see from Focus Figure 2.2, if a nutrient’s requirements were set using the EAR, 50 percent of the individuals would need more and 50 percent would need less than this amount to meet their needs.

An EAR for each nutrient is established based on a measurement that indicates whether an individual is at risk of a deficiency. For example, to determine the EAR for iron for a 19-year-old female, scientists measure hemoglobin concentrations in the blood. The measurement differs from nutrient to nutrient. If there aren’t enough stud- ies or collected data to develop an appropriate measurement for a nutrient, an EAR or requirement for that nutrient is not established. Once the EAR has been set for each nutrient, the RDA can be calculated.

Recommended Dietary Allowances The Recommended Dietary Allowance (RDA) is based on the EAR, but it is set higher. It represents the amount for each nutrient that should meet the needs of nearly all (97–98 percent) of the individuals in a specific gender and age group. Let’s use iron to illustrate the relationship between the EAR and the RDA. After careful review of the latest research on iron metabolism, the EAR for iron was set at 6 milligrams per day for both men and women over all age groups.13 The amount is increased to an RDA of 18 milligrams per day to cover the needs of 97 to 98 percent of females ages 19–30. For 19- to 30-year-old males, the RDA for iron is 8 milligrams daily. The RDA for each nutrient according to age and gender is presented in the front of the textbook.

If there is insufficient evidence to determine an EAR for a nutrient, the RDA can’t be calculated. When this is the case, such as with fluoride, an Adequate Intake can pro- vide an alternative guideline.

Adequate Intakes Adequate Intake (AI) is a formal reference value that is estimated based on the judg- ment of the members of the FNB, according to the latest research. The AI is the next best scientific estimate of the amount of a nutrient that groups of similar individuals should consume to maintain good health.

There are several differences between the RDAs and the AIs. First, the RDAs are based on EARs, whereas the AIs are set without having established an EAR. If a nutrient

Estimated Average Requirement (EAR) Average daily amount of a nutrient needed by 50 percent of the individuals in a similar age and gender group.

Recommended Dietary Allowance (RDA) Recommended daily amount of a nutri- ent that meets the needs of nearly all individu- als (97–98 percent) in a similar age and gender group. The RDA is set higher than the EAR.

Adequate Intake (AI) Approximate daily amount of a nutrient that is sufficient to meet the needs of similar individuals within a popula- tion group. The Food and Nutrition Board uses AIs for nutrients that do not have enough sci- entific evidence to calculate an RDA.

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46 Chapter 2 | Tools for Healthy Eating

Head to Mastering Nutrition and watch a narrated video tour of this figure by author Joan Salge Blake.

Figure 2.2 Dietary Reference IntakesFOCUS

Increased risk of toxicity

Increasing amount of nutrient

Percentage of total energy intake for adults

100 20 30 40 50 60 70 80 90 100

N um

be r o

f i nd

iv id

ua ls

in a

s pe

ci fic

ag

e an

d ge

nd er

g ro

up

Dietary Reference Intakes (DRIs) are specific reference values for each nutrient issued by the Food and Nutrition Board of the National Academy of Medicine. They identify the amounts of each nutrient that one needs to consume to maintain good health.

DRIs FOR MOST NUTRIENTS

DRIs RELATED TO ENERGY

EER The Estimated Energy Requirement (EER) is the average daily energy intake predicted to meet the needs of healthy adults.

AMDR The Acceptable Macronutrient Distribution Range (AMDR) is the recommended range of carbohydrate, fat, and protein intake expressed as a percentage of total energy.

EAR The Estimated Average Requirement (EAR) is the average daily intake level estimated to meet the needs of half the people in a certain group. Scientists use it to calculate the RDA.

RDA The Recommended Dietary Allowance (RDA) is the average daily intake level estimated to meet the needs of nearly all people in a certain group. Aim for this amount!

AI The Adequate Intake (AI) is the average daily intake level assumed to be adequate. It is used when an EAR cannot be determined. Aim for this amount if there is no RDA!

UL The Tolerable Upper Intake Level (UL) is the highest average daily intake level likely to pose no health risks. Do not exceed this amount on a daily basis!

Carbohydrates 45–65%

Protein 10–35%

Fat 20–35%

AMDR

EAR (Meets nutrient

needs for 50% of individuals)

RDA (Meets nutrient

needs for 97–98% of individuals)

UL

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What Are the Dietary Reference Intakes? 47

has an AI, then more research must be done to accurately set an RDA. Second, the RDAs should cover the needs of 97–98 percent of the population, but the AIs do not estimate how many people will be covered because the EAR is not available. Finally, for infants, AIs are the only estimations for nutrients to evaluate dietary adequacy. This is because conducting the types of studies necessary to determine an EAR would be unethical.

The nutrients with AIs are noted in the DRI tables in the front of your textbook and include some vitamins and minerals, such as biotin, pantothenic acid, vitamin K, fluoride, and potassium.

Tolerable Upper Intake Level Because consuming too much of some nutrients can lead to harmful side effects, the FNB developed the Tolerable Upper Intake Level (UL). The Tolerable Upper Intake Level is not a recommended intake. It refers to the highest amount of a nutrient that is unlikely to cause harm if consumed daily. The higher the consumption above the UL, the higher the risk of toxicity. These reference values became necessary because of indi- viduals’ increased interest in consuming dietary supplements and fortified foods in pur- suit of their supposed health benefits. For example, the American Association of Poison Control Centers report approximately 60,000 annual cases of vitamin toxicity from dietary supplements.14 Unfortunately, many Americans believe that vitamin supplements are safe in any dose but that consuming too much of other nutrients, such as fat or cho- lesterol, can have a deleterious effect.

Not all nutrients have UL values. This doesn’t mean that high intakes of those nutri- ents are safe, however.  The UL for selected nutrients according to age and gender is presented in the front of the textbook.

Acceptable Macronutrient Distribution Ranges To ensure that intake of the energy nutrients is adequate and proportionate to physi- ological needs, recommended ranges of carbohydrate, fat, and protein intakes have been developed. These are called the Acceptable Macronutrient Distribution Ranges (AMDRs). The AMDRs are as follows:

• Carbohydrates should comprise 45–65 percent of your daily kilocalories • Fat should comprise 20–35 percent of your daily kilocalories • Proteins should comprise 10–35 percent of your daily kilocalories

Consuming the energy-yielding nutrients in these ranges will ensure that kilocalorie and nutrient needs are met, while the risk of developing chronic diseases such as heart disease and obesity is reduced.15 Practice calculating the AMDR using the Calculation Corner. (We cover this in greater detail in Chapter 14.)

Estimated Energy Requirements No DRI has been established for energy (kilocalorie) intake. The method used to deter- mine the amount of energy you need, or your Estimated Energy Requirement (EER), uses a different approach than the RDAs or AIs. The EER is calculated based on age, gender, height, weight, and activity level and indicates the amount of energy needed to maintain energy balance. Individuals who consume more energy than they need will gain weight. Equations to provide a general estimate of energy needs are included in Chapter 14.

You Can Use the DRIs to Plan a Quality Diet You can use the DRIs to make healthy food choices and plan a quality diet. To meet your needs, your goal should be to achieve the RDA or the AI of all nutrients, but not exceed the UL. Table 2.3 summarizes how to use the DRIs to plan a quality diet. (You will also find the DRIs for all nutrients on the inside front cover of this textbook.)

Tolerable Upper Intake Level (UL) Maximum daily amount of a nutrient consid- ered safe in a group of similar individuals.

toxicity Level of nutrient intake at which expo- sure to a substance becomes harmful.

Acceptable Macronutrient Distribution Ranges (AMDRs) Healthy range of intakes for the energy-containing nutrients—carbohydrates, proteins, and fats—expressed as a percentage of total daily energy. The AMDRs for adults are 45–65 percent carbohydrates, 10–35 percent protein, and 20–35 percent fat.

Estimated Energy Requirement (EER) Amount of daily energy to maintain a healthy body weight and meet energy needs based on age, gender, height, weight, and activity level.

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48 Chapter 2 | Tools for Healthy Eating

Each chapter in this textbook further explains what each nutrient is, why it is impor- tant, how much (based on the DRIs) you need to consume, and how to get enough, with- out consuming too much, in your diet.

Calculation Corner

Calculating AMDR Use the following scenario to calculate the AMDR for carbohydrate and fat:

Suppose a woman needs 2,150 kcal per day to maintain her current healthy weight. The AMDR for carbohydrates is 45–65 percent of total daily kilocalories. To determine the

number of kilocalories she needs to obtain daily from carbohydrates, we run the following equations:

2,150 kcal * 45 percent carbohydrates = 2,150 * 0.45 = 968 kcal 2,150 kcal * 65 percent carbohydrates = 2,150 * 0.65 = 1,398 kcal

Thus, of the 2,150 kcal the woman eats each day, 968–1,398 kcal should be from carbohydrates.

The AMDR for fat is 20–35 percent of daily kilocalories. Therefore:

2,150 kcal * 20 percent fats = 2,150 * 0.20 = 430 kcal 2,150 kcal * 35 percent fats = 2,150 * 0.35 = 753 kcal

Of the 2,150 kcal the woman eats each day, 430–753 kcal should be from fat.

Can you calculate the AMDR for your daily intake of kilocalories?

Reference Value When Planning Your Diet

Estimated Average Requirement (EAR) Don’t use this amount.

Recommended Dietary Allowance (RDA) Do aim for this amount!

Adequate Intake (AI) Do aim for this amount if an RDA isn’t available.

Tolerable Upper Intake Level (UL) Don’t exceed this amount on a daily basis.

Acceptable Macronutrient Distribution Range (AMDR)

Do follow these guidelines regarding the percentage of carbohydrates, protein, and fat in the diet.

Source: Adapted from the Subcommittee on Interpretation and Uses of Dietary Reference Intakes and the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, Institute of Medicine and Food and Nutrition Board. 2003. Dietary Reference Intakes: Applications in Dietary Planning. Washington, DC: National Academics Press. Reprinted with permission.

TABLE 2.3 The Do’s and Don’ts of the DRIs

LO 2.2: THE TAKE-HOME MESSAGE The Dietary Reference Intakes are specific reference values that help individuals determine daily nutrient needs to maintain good health, prevent chronic diseases, and avoid unhealthy excesses. The reference values include the EAR, RDA, AI, UL, and AMDR. The EER can help determine the appropriate amount of energy needed to maintain a healthy body weight given one’s age, gender, height, weight, and activity levels. You should try to meet your RDA or AI and consume below the UL for each nutrient daily while maintaining sufficient energy intake.

Go to Mastering Nutrition and complete a Math Video activity similar to the problem in this Calculation Corner.

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What Is MyPlate? 49

What Are the Dietary Guidelines for Americans? LO 2.3 Describe the recommendations included in the Dietary Guidelines for

Americans.

Whereas the DRIs were released to prevent undernutrition, the Dietary Guidelines for Americans were developed out of concern over the incidence of overnutrition among Americans. By the 1970s, research had shown that Americans’ overconsumption of foods rich in saturated fat, cholesterol, and sodium was increasing their risk for chronic diseases such as heart disease and stroke.16 In 1977, the U.S. government released the Dietary Goals for Americans, which were designed to improve the nutritional quality of Americans’ diets and to try to reduce the incidence of overnutrition and its associated health problems.17

Amid controversy over the scientific validity of the goals, the government asked scien- tists to participate in the next revision. Their work culminated in the 1980 Dietary Guidelines for Americans, which emphasized eating a variety of foods to obtain a nutritionally balanced diet. Since 1990, the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS) have been mandated by law to update the guidelines every 5 years. The guidelines shape all federally funded nutrition programs in areas such as research and labeling and educate consumers about healthy diet and lifestyle choices.18

The Dietary Guidelines for Americans are designed to help individuals age 2 and over improve the quality and content of their diet and make other lifestyle choices to lower their risk of chronic diseases and conditions, such as diabetes mellitus, cardiovascular disease, certain cancers, osteoporosis, and obesity.

The most recent guidelines build on the previous reports and encourage Americans to follow healthy eating patterns. They also include updated guidance on added sugars, sodium, cholesterol, and caffeine.19 The Spotlight on page 50 provides an overview of the current dietary guidelines.

Dietary Guidelines for Americans Guidelines published every 5 years by the Department of Health and Human Services and the United States Department of Agricul- ture that provide dietary and lifestyle advice to healthy individuals age 2 and older to maintain good health and prevent chronic diseases. They are the basis for the federal food and nutrition education programs.

LO 2.3: THE TAKE-HOME MESSAGE The Dietary Guidelines for Americans reflect the most current nutrition and lifestyle advice for good health and reduced risk for chronic disease. They are updated by the USDA and HHS every 5 years.

What Is MyPlate? LO 2.4 Discuss the concept of MyPlate, including the food

groups and typical foods represented.

Released in 2011, MyPlate is an icon that serves as a reminder for healthy eating (Figure 2.3). Its online component, ChooseMyPlate.gov, is a Web- based communication and education initiative that provides information, tips, and tools to help people build a diet based on the DGAs and the DRIs. These include an interactive tool based on the USDA Food Patterns, which identify the amounts of food to consume from each of the basic food groups, as well as oils, at a range of kilocalorie levels, in order to pro- vide a balanced diet. Together, the MyPlate icon and accompanying web- site promote proportionality, moderation, variety, and personalization.

MyPlate Icon that serves as a reminder for healthy eating and a website providing nutri- tional information and educational tools based on the Dietary Guidelines for Americans and the Dietary Reference Intakes (DRIs).

▶ Figure 2.3 Anatomy of MyPlate The MyPlate icon reinforces important concepts of healthful choices, propor- tionality, and moderation to be used in planning a healthful diet. Source: U.S. Department of Agriculture. 2011. ChooseMyPlate.gov.

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50 Chapter 2 | Tools for Healthy Eating

Dietary Guidelines for Americans, 2015–2020SPOTLIGHT

The Dietary Guidelines encourage consumption of a variety of fruits and vegetables.

The Dietary Guidelines for Americans, 2015–2020 (DGAs) provide evidence-based guid- ance to Americans ages 2 and older to achieve an adequate, healthy diet. The following is a short overview of the recommendations. The complete guide- lines are available at http://health.gov/ dietaryguidelines/2015/guidelines/.

The DGAs have three primary objectives:

• Promote health • Prevent chronic disease • Help people reach and maintain a

healthy weight

To achieve these objectives, five spe- cific guidelines are included with accom- panying key recommendations.

1. Follow a healthy eating pattern across the lifespan. All food and beverage choices mat- ter. Choosing a healthy eating pattern at an appropriate kilocalorie level can help individuals achieve and maintain a healthy body weight; support nutri- ent adequacy; and reduce the risk of chronic disease.

The Dietary Guidelines emphasize that healthy eating patterns are adaptable. Examples include Mediterranean-style diets, vegetarian diets, the DASH diet, and many others that we discuss later in this text.

2. Focus on variety, nutrient density, and amount. To meet nutrient and kilocalorie needs, Americans should eat a variety of nutrient- dense foods both across and within food groups in recommended amounts.

The typical American diet does not align with the Dietary Guidelines. Spe- cifically, about three-fourths (75%) of Americans eat a diet that is low in veg- etables, fruits, dairy, and oils and exceeds total grain and protein recommendations. Moreover, excess weight affects two- thirds (70%) of adults and one-third (30%) of children in the United States. Thus,

Americans should focus on consuming nutrient-dense, lower- energy foods, and pay attention to portion sizes—the amount of foods and drinks they consume during meals and snacks. Individu- als can determine their kilocalorie and nutri- ent needs based on their age, gender, and activity level, and find recommendations for portion sizes by using the ChooseMyPlate website.

3. Limit kilocalories from added sugars and saturated fats and reduce sodium intake. On average, Americans consume too many kilocalories from foods high in added sugars and saturated fat, which displace healthier foods, like fruits, vegetables, and whole grains, and contribute to excessive energy intake overall. Accordingly, the DGAs recom- mend that individuals limit their intake of added sugars and saturated fat to 10 percent or less of total kilocalorie intake. To decrease added sugar intake, read labels on processed foods, espe- cially beverages, snacks, sweets, and refined grains, as these foods contrib- ute the majority of added sugars to the American diet. To decrease saturated fat intake, limit consumption of but- ter, lard, full-fat cheese, whole milk, ice cream, fatty meats, poultry skin, baked goods, and mixed dishes such as pizza, burgers, and meat dishes.

Americans should also limit their sodium intake to 2,300 mg/day. Americans of all ages consume too much sodium. Sodium is a public health concern in the United States because of its relationship with high blood pressure (hypertension) and kidney disease.

Other dietary components to limit include:

• Alcohol. Adults of legal drinking age should consume no more than one drink per day for nonpregnant women or two drinks per day for men.

• Trans fats. Because trans fats are associated with an increased risk for cardiovascular disease, Americans should keep their trans fat intake as low as possible by avoiding products made with partially hydrogenated oils (PHOs), such as margarines and certain processed baked goods. The FDA no longer recognizes PHOs as safe and requires that food companies remove them from their products by the summer of 2018.

• Dietary cholesterol. The DGAs do not include a recommended limit on cholesterol intake, but suggest that Americans should eat as little dietary cholesterol as possible.

• Caffeine. Moderate consumption of caffeine (400 mg/day) can be incorpo- rated into a healthy eating pattern.

4. Shift to healthier food and beverage choices. Replace foods and beverages that are high in kilocalories, sugar, salt, and/or

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DGAs, everyone has a role to play. Col- lective action is needed at home, at school, at work, in the community, and at food retail outlets to ensure that all Americans have access to healthy foods that are both affordable and familiar. To help in these efforts, Americans are encouraged to create settings where healthy choices are available and afford- able in the home, school/work, or community.

These small changes could have a big impact on health over time. Tips for changing intake habits within each food group can be found at www.choosemy plate.gov/start-small-changes.

5. Support healthy eating patterns for all. In order for Americans to successfully adopt the key recommendations in the

saturated fats with those that are more nutrient-dense both across and within all food groups.

Examples include replacing:

• Chips and dip S Carrots and hummus • Apple-flavored cereal bar S Apple • White bread S Whole-wheat bread • Sugar-sweetened beverages S Water • Butter S oils • Whole milk S Low@fat or skim milk

MyPlate Emphasizes Changes in Diet As you can see in Figure 2.3, MyPlate shows a place setting split into five colored sec- tions, with each representing one of five food groups: fruits, vegetables, grains, protein, and dairy. Notice that the proportionality of these food groups supports a plant-based diet: half of the plate is devoted to vegetables and fruits, and a quarter of the plate is devoted to grains. Lean protein foods such as fish, skinless poultry, lean meats, and legumes make up a quarter of the plate. Whereas oils are an important part of a healthy diet, they are not represented on the plate, as they are not considered a food group. The blue circle next to the plate is a visual reminder to consume fat-free and low-fat dairy foods such as milk at mealtimes.

Shifting the food proportionality on your plate can have a dramatic effect on your kilocalorie intake and thus on your weight and your risk for chronic disease. Devoting at least half of the surface of the plate to lower-kilocalorie fruits and vegetables balances higher-kilocalorie grains and protein food choices. Take the Self-Assessment to see how well proportioned your diet is.

proportionality Relationship of one entity to another. Vegetables and fruits should be con- sumed in a higher proportion than dairy and protein foods in the diet.

Self-Assessment

Does Your Diet Have Proportionality? Answer “yes” or “no” to the following questions:

1. Are grains the main food choice at all your meals?

Yes  □  No  □

2. Do you often forget to eat vegetables?

Yes  □  No  □

3. Do you typically eat fewer than three servings of fruit daily?

Yes  □  No  □

4. Do you often have fewer than three cups of milk, yogurt, and/or calcium-fortified soymilk daily?

Yes  □  No  □

5. Is the portion of meat, chicken, or fish the largest item on your dinner plate?

Yes  □  No  □

Answer If you answered “yes” to three or more of these questions, it is very likely that your diet lacks proportionality. You can use the information in this chapter to help improve the proportionality of your diet.

What Is MyPlate? 51

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52 Chapter 2 | Tools for Healthy Eating

Individuals who choose high-nutrient-dense and low-energy-dense foods will gen- erally have diets that are also lower in saturated fats and added sugars. Figure 2.4 helps you compare some nutrient-dense food choices with less healthy food choices in each food group. As you look at the figure, notice which foods are, by contrast, energy dense.

Eating a variety of foods among and within the food groups highlighted in MyPlate will increase your chances of consuming all 40 of the nutrients your body needs. Figure 2.5 provides tips on how to choose a variety of foods from each food group.

▲ Figure 2.4 Nutrient-Dense Food Choices Choose nutrient-dense foods more often to build a balanced diet.

Eat less of these

Eat more of these

Foods with high amounts of added sugars and heart- unhealthy solid fats. These are less nutrient dense.

Foods that are more nutrient dense.

Buttered popcorn, cake, cookies, donuts, pastries

French fries, potato chips

Fruit canned in syrup, fruit drinks, sweetened dried fruit

Butter, hydrogenated oils

Full-fat cheeses, fried mozzarella sticks, high-fat ice cream

Fatty cuts of meat and luncheon meats, fried chicken or fish, poultry with skin

Brown rice, bulgur, couscous, oats, pasta, popcorn, rice, whole-grain cereals, bread, crackers

Fresh, frozen and canned vegetables, dried beans and peas

Dried beans and peas, eggs, fish, lean meat, nuts, skinless poultry, seeds

Vegetable oilsLow-fat or nonfat cheese, milk or yogurt, low-fat ice cream or frozen yogurt

Dried fruit, whole fruit, 100% fruit juice

GrainsVegetables Fruits Protein OilsDairy

▶ Figure 2.5 Mix Up Your Choices within Each Food Group Source: USDA Consumer Brochure. 2005. Finding Your Way to a Healthier You. Based on the Dietary Guidelines for Americans. Accessed February 2017.

Focus on fruits. Eat a variety of fruits—whether fresh, frozen, canned, or dried—rather than fruit juice for most of your fruit choices. For a 2,000-calorie diet, you will need 2 cups of fruit each day (for example, 1 small banana, 1 large orange, and 1/4 cup of dried apricots or peaches).

Vary your veggies. Eat more dark green veggies, such as broccoli, kale, and other dark leafy greens; orange veggies, such as carrots, sweet potatoes, pumpkin, and winter squash; and beans and peas, such as pinto beans, kidney beans, black beans, garbanzo beans, split peas, and lentils.

Get your calcium-rich foods. Get 3 cups of low-fat or fat-free milk—or an equivalent amount of low-fat yogurt and/or low-fat cheese (11/2 ounces of cheese equals 1 cup of milk)—every day. For kids aged 2 to 8, it’s 2 cups of milk. If you don’t or can’t consume milk, choose lactose-free milk products and/or calcium-fortified foods and beverages.

Go lean with protein. Choose lean meats and poultry. Bake it, broil it, or grill it. And vary your protein choices—with more fish, beans, peas, nuts, and seeds.

Make half your grains whole. Eat at least 3 ounces of whole-grain cereals, breads, crackers, rice, or pasta every day. One ounce is about 1 slice of bread, 1 cup of breakfast cereal, or 1/2 cup of cooked rice or pasta. Look to see that grains such as wheat, rice, oats, or corn are referred to as “whole” in the list of ingredients.

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What Is MyPlate? 53

Lastly, physical activity is an important component of a healthy lifestyle. Being physically active (see Table 2.4) helps you stay fit and reduce your risk of obesity and chronic diseases such as heart disease and cancer. Advice regarding physical activity can be found at http://ChooseMyPlate.gov.

Use MyPlate to Choose Foods that Fit Your Kilocalorie Needs You now know to eat a variety of nutrient-dense foods to be healthy and that MyPlate helps you select a diverse group of foods, but you may be wondering how much from each food group you should be eating. The ChooseMyPlate.gov interactive website will give you the exact numbers of servings to eat from each food group based on your daily kilocalorie needs. If you cannot go to the website, Table 2.5 tells you the quantity from each food group you should consume to healthfully obtain the daily kilocalories you need.

Examples of Moderate Activities (Expend 3.5 to 7 Kilocalories per Minute):

Examples of Vigorous Activities (Expend More Than 7 Kilocalories per Minute):

• Brisk walking • Bicycling 5–9 mph • Shooting hoops • Using free weights • Yoga • Walking a dog

• Jogging or running • Bicycling more than 10 mph • Playing competitive sports like basket-

ball, soccer, or lacrosse • Rowing on a machine vigorously • Karate, judo, or tae kwon do • Jumping rope

Source: Adapted from the Centers for Disease Control and Prevention. 2015. Physical Activity for a Healthy Weight. Available at www.cdc.gov. Accessed February 2017.

TABLE 2.4 What Is Moderate and Vigorous Activity?

Kilocalorie Level Grains (oz eq) Vegetables (cups) Fruits (cups) Oils (tsp) Dairy (cups) Protein (oz eq)

1,400 5 1.5 1.5 4 2 4

1,600 5 2 1.5 5 3 5

1,800 6 2.5 1.5 5 3 5

2,000 6 2.5 2 6 3 5.5

2,200 7 3 2 6 3 6

2,400 8 3 2 7 3 6.5

2,600 9 3.5 2 8 3 6.5

2,800 10 3.5 2.5 8 3 7

The above are suggested amounts to consume daily from each of the basic food groups and the oils based on daily kilocalorie needs. Remember that most food choices should be fat free or low fat and contain little added sugar.

Note: Grains: Includes all foods made with wheat, rice, oats, cornmeal, or barley, such as bread, pasta, oatmeal, breakfast cereals, tortillas, and grits. In general, 1 slice of bread, 1 cup of ready-to-eat cereal, or 1⁄2 cup of cooked rice, pasta, or cereal is considered 1 ounce equivalent (oz eq) from the grains group. At least half of all grains consumed should be whole grains such as whole-wheat bread, oats, or brown rice.

Vegetables: Includes all fresh, frozen, canned, and dried vegetables, including legumes, as well as vegetable juices. In general, 1 cup of raw or cooked vegetables or vegetable juice, or 2 cups of raw leafy greens, is considered 1 cup from the vegetable group.

Fruits: Includes all fresh, frozen, canned, and dried fruits and fruit juices. In general, 1 cup of fruit or 100% fruit juice, or 1⁄2 cup of dried fruit, is considered 1 cup from the fruit group.

Oils: Includes vegetable oils such as canola, corn, olive, soybean, and sunflower oil, fatty fish, nuts, avocados, mayonnaise, salad dressings made with oils, and soft margarine.

Dairy: Includes all fat-free and low-fat milk and calcium-fortified soymilk, as well as yogurt and cheese. In general, 1 cup of milk or yogurt, 11⁄2 ounces of natural cheese, or 2 ounces of processed cheese is considered 1 cup from the dairy group.

Proteins: In general, 1 ounce of lean meat, poultry, or fish, 1 egg, 1 tablespoon peanut butter, 1⁄4 cup cooked dry beans, or 1⁄2 ounce of nuts or seeds is considered 1 ounce equiva- lent (oz eq) from the protein group.

Source: U.S. Department of Agriculture. 2017. Available at https://health.gov/dietaryguidelines/2015/resources/2015-2020_Dietary_Guidelines.pdf.

TABLE 2.5 How Much Should You Eat from Each Food Group?

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54 Chapter 2 | Tools for Healthy Eating

For example, for a moderately active female who needs 2,000 kilocalories daily, a healthy daily diet would consist of the following:

• 6 servings from the grains group • 21⁄2 cups of dark green, orange, starchy, and other vegetables, including some

legumes • 2 cups of fruits • 3 cups of fat-free or low-fat milk, calcium-fortified soymilk, and/or yogurt • 51⁄2 ounces of lean meat, poultry, and fish, or the equivalent in meat alterna-

tives such as beans • 6 teaspoons of vegetable oils

The kilocalorie levels and distribution of food groups in daily food plans are calculated using the leanest food choices with no added sugar. If all food selec- tions are low in fat and added sugar, this menu will provide a total of about 1,740 kilocalories (Figure 2.6). If you pour whole milk (high in fat) over your sweet- ened cereal (added sugar) instead of using skim milk (fat free) to drench your shred- ded wheat (no added sugar), the extra fat and sugar kilocalories add up quickly to reach 2,000 kilocalories (Table 2.6).

Figure 2.7 shows how servings from the various food groups can create well- balanced meals and snacks throughout the day. Although this particular menu is balanced and the foods are nutrient dense, it is unlikely that every day will be this ideal. Fortunately, nutrient needs are averaged over time. If you eat insufficient serv- ings of one food group or a specific nutrient one day, you can make up for it the next day.

Should you worry about when you eat? This question is debated in Examining the Evidence: Does the Time of Day You Eat Impact Your Health? on pages 56–57.

▲ Figure 2.6 How Fats and Added Sug- ars Fit into a Balanced Diet If you select mostly nutrient-dense, lean foods that contain few saturated fats and added sugars, you may have leftover kilocalories to “spend” on extra helpings or a sweet dessert.

1,740 kilocalories (lean foods without added sugars)

260 kilocalories (added fats and sugars)

2,000 total daily kilocalories

Choosing . . . Over . . . Will Cost You

Whole milk (1 cup) Fat-free milk (1 cup) 65 kilocalories

Roasted chicken thigh with skin (3 oz)

Roasted chicken breast, skin- less (3 oz)

70 kilocalories

Glazed doughnut (3 3⁄4" diameter) English muffin (one muffin) 165 kilocalories

French fries (one medium order) Baked potato (one medium) 299 kilocalories

Regular soda (one can, 12 fl oz) Diet soda (one can, 12 fl oz) 150 kilocalories

Note: As you can see, your daily food plan can include saturated fats and added sugars, depending on food choices. Source: Adapted from the U.S. Department of Agriculture, MyPlate. “Empty Calories: How Do I Count the Empty Calories I Eat?” 2011. Available at www.ChooseMyPlate.gov.

TABLE 2.6 Choose Right

LO 2.4: THE TAKE-HOME MESSAGE MyPlate depicts the five food groups using the familiar mealtime visual of a place setting. It is part of the USDA’s Web-based initiative at ChooseMyPlate.gov, providing information and tools, including personalized daily food plans, to help you build a healthy diet based on the Dietary Guidelines for Americans. Try to consume nutrient-dense foods—fruits, vegetables, whole grains, and lean dairy and protein foods—but limit energy-dense foods, which provide kilocalories from saturated fats and added sugars but little nutrition. Daily physical activity is encouraged to better manage your weight and health.

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What Is the Exchange System? 55

What Is the Exchange System? LO 2.5 Explain how the exchange system can be used as a guide to plan a

balanced diet.

The exchange lists for meal planning were designed in 1950 to give people with diabetes a structured, balanced eating plan. The lists, which are still in use today, group foods accord- ing to their carbohydrate, protein, and fat composition and provide specific portion sizes for each food. In addition, each food in the group has a similar number of kilocalories.

There are six food groups in the exchange lists: starch, fruit, milk, vegetable, meat, and fat. You might be surprised to find some foods located in unexpected places. For example, in MyPlate, cheese is in the milk group because of its calcium content. In the exchange system, cheese is in the meat group because it has less carbohydrate than milk or yogurt but contains levels of protein and fat similar to those found in chicken or meat. Potatoes are not found in the vegetable list, but in the starch list; bacon is considered a fat exchange because it contains more fat than protein; and peanut butter is found in both the high-fat meat list and the fat list because it is high in both protein and fat.

exchange lists Diet-planning tool that groups foods together based on their carbohydrate, protein, and fat content. One food on the list can be exchanged for another food on the same list.

▲ Figure 2.7 A Healthy Daily Food Plan A variety of foods from each food group creates a balanced diet.

GrainsBreakfast

Lunch

Dinner

Vegetables DairyProteinFruits O ils

Bran flakes, 1 cup Whole-wheat English mu�n, 1/2

Banana, 1 small Orange juice, 1 cup

S of

t m ar

ga rin

e, 1

ts p

S of

t m ar

ga rin

e, 1

ts p

S un

flo w

er o

il, 3

ts p

GrainsVegetables DairyProteinFruits O ils

Whole-wheat bread, 2 slices

Diced celery, 1 tbs Romaine lettuce, 1/2 cup Tomatoes, 2 slices

Fat-free milk, 1 cup

Fat-free milk, 1 cup

Tuna (packed in water), 2.5 oz

Pear, 1 medium

M ay

on na

is e,

2 ts

p

Snack GrainsVegetables DairyProteinFruits O ils

Low-fat vanilla yogurt, 1 cup

Dried apricots, 1/4 cup

GrainsVegetables DairyProteinFruits O ils

Dinner rolls, 2 1 oz each

Baked sweet potato, 1 large Peas and onions, 1/2 cup Leafy green salad, 1 cup

Roasted chicken breast (boneless and skinless), 3 oz

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56 Chapter 2 | Tools for Healthy Eating

EXAMINING THE

EVIDENCE

We are all creatures of habit. Some of our habits, such as the time of day we eat, can either enhance or detract from our health. Do you skip a meal daily? Do you find yourself snacking late at night? Do you overload on high-fat or fried foods or drink a lot of alcohol when you go out on the weekends? These kinds of choices can affect your body weight, nutrient intake, and health.

Snacking and Skipping Breakfast While your grandparents may have habitually had their “three square meals” (breakfast, lunch, and din- ner) daily with little snacking between meals, this pattern has changed over the last several decades. In a study looking at the eating habits of over 32,000 adult women during a 40-year span, the incidence of eating three meals a day declined from 75 percent to 63 percent among the women, but the incidence of snacking increased.1 This is a concern because snack- ing has been associated with the

consumption of excess kilocalories and obesity.2 Interestingly, the incidence of obesity among these women during this time period more than doubled.3

Skipping breakfast specifically may reduce the nutrient quality of your diet.4

In contrast, children who eat a healthy breakfast on a regular basis are better able to meet their intake of food groups such as dairy and fruit and their daily needs for essential micronutrients such as thiamin, niacin, riboflavin, vitamins B6 and B12, cal- cium, iron, magnesium, potassium, and zinc.5,6

Eating More at Night and on Weekends There may be something to the old adage to eat breakfast like a king, lunch like a prince, and dinner like a pauper when it comes to better managing your weight. Researchers stud- ied how switching between a high-kilocalorie breakfast and a high-kilocalorie din- ner, but keeping the total daily kilocalories the same, would influence body

weight.7 In this 12-week study, 50 over- weight women were randomly assigned to a 1,400-kilocalorie diet that consisted of a breakfast of 700 kilocalories, a lunch of 500 kilocalories, and a dinner of 200 kilocalories or the same kilocalo- ries and same food choices but with the breakfast and dinner meals switched.8

While both groups lost significant amounts of weight, the women consum- ing the large breakfast lost an average of approximately 19 pounds compared to only about 8 pounds in the large dinner group. The large breakfast group also lost twice as many inches around their waists. Since the hormone ghrelin, which increases your appetite, was lower dur- ing the day in the breakfast group, these women also experienced higher levels of satiety throughout the day. In addition, large breakfast eaters also had signifi- cantly lower levels of insulin, glucose, and fat in their blood, which may help lower the risk of diabetes and heart disease.9

A factor in the weight-loss differ- ence may be the body’s circadian rhythms, which are hormonal, meta- bolic, mental, and behavioral changes that the body follows over a 24-hour cycle.10,11 Consequently, the time of day we eat may affect the way our bodies process food. More research is needed before any strong conclu- sions can be drawn from these results.

Does the Time of Day You Eat Impact Your Health?

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Do you eat after 7:00 p.m.? Most young adults do, especially during the weekend.12 For most students, eating schedules are influenced by hun- ger, pressures from work and school, convenience, and social habits. Studies suggest that the craving for late-night carbohydrate snacks is also related to your circadian rhythms.13 Also, when eating later in the day, you are likely to eat more food, and hence consume more kilocalories, particularly from carbohydrates, fat, and alcohol.

Weekend eating patterns can also influence overall dietary intake. Haines reports that people in their study ate an average of 82 kilocalories more per day on Friday, Saturday, and Sunday compared with weekdays.14 These increases in kilocalories were mostly due to an increase in fat (approximately 0.7 percent) and alcohol (1.4 percent); carbohydrates decreased by 1.6 per- cent. Over time, this increase in kilo- calorie intake may lead to weight gain. Results from a similar study involving over 11,500 adults suggest that Sat- urday is the day with the highest kilo- calorie consumption.15 Compared to the average weekday consumption, the adults consumed 181 kilocalories more on Saturday, on average, with over 40 percent of the kilocalories coming from sugar-sweetened beverages, alcohol, sugar, and saturated fat. Not surpris- ing, eating fast foods and dining out in restaurants was higher on Saturday than any other day of the week.16

Recommendations Based on the current research on eating and time of day, it is recommended that you:

• Start your day with a nutrient-dense breakfast as part of a healthy eating pattern. Many breakfast foods—such as dry whole-grain cereals, fresh fruit, or whole-grain toast or bagels with low-fat cream cheese—can be eaten on the go. You’ll have more energy and will most likely eat fewer total kilo- calories by the end of the day.

• Choose breakfast foods that are more satisfying to improve your appetite con- trol throughout the day. Enjoy foods such as whole-grain cereals and whole fruits, which are higher in fiber, protein, and water and lower in fat and sugar.

• Control kilocalorie intake on nights and weekends. Monitor your weekend eating habits to maintain a consistent balance of carbohydrates, fats, and proteins and to reduce alcohol consumption.

References 1. Kant, A., and B. Graubard. 2015. 40-Year

Trends in Meal and Snack Eating Behaviors of American Adults. Journal of the Academy of Nutrition and Dietetics 115:50–63.

2. Piernas, C., and B. Popkin. 2010. Snack- ing Increased Among U.S. Adults Between 1977–2006. Journal of Nutrition 140:325–332.

3. Kant, 2015. 4. St-Onge, M., J. Ard, M. Baskin, S. Chiuve, H.

Johnson, P. Kris-Etherton, and K. Varady. 2017. Meal Timing and Frequency: Implica- tions for Cardiovascular Disease Prevention. A scientific Statement from the American Heart Association. DOI:10.1161.

5. USDA, Center for Nutrition Policy and Promotion. 2011. Breakfast Consumption, Body Weight, and Nutrient Intake: A Review of the Evidence. Available at https://www.cnpp .usda.gov/sites/default/files/nutrition_ insights_uploads/Insight45.pdf. Accessed February 2017.

6. Dykstra, H., A. Davery, J. Fisher, H. Polonsky, S. Sherman, M. Abel, L. Dale, G. Foster, and K. Bauer. 2016. Breakfast-Skipping and Selecting Low Nutritional-Quality Foods for Breakfast Are Common Among Low-Income Urban Children, Regardless of Food Security Status. Journal of Nutrition 146:630–636.

7. Jakubowicz, D., M. Barnea, J. Wanstein, and O. Froy. 2013. High Caloric Intake at Breakfast vs. Dinner Differentially Influ- ences Weight Loss of Overweight and Obese Women. Obesity 21:2504–2512.

8. Ibid. 9. Ibid. 10. Ibid. 11. Covassin, N., P. Singh, and V. Somers. 2016.

Keeping Up With the Clock: Circadian Disruption and Obesity Risk. Hypertension 68:1081–1090.

12. Striegel-Moore, R. H., D. L. Franko, D. Thompson, S. Affenito, and H. C. Krae- mer. 2006. “Night Eating: Prevalence and Demographic Correlates.” Obesity 14:139–147.

13. Scheer, Frank A. J. L., Christopher J. Morris, and Steven A. Shea. 2013. “The Internal Cir- cadian Clock Increases Hunger and Appetite in the Evening Independent of Food Intake and Other Behaviors.” Obesity 21(3):421.

14. Haines, P. S., M. Y. Hama, D. K. Guilkey, and B. M. Popkin. 2003. “Weekend Eating in the United States Is Linked with Greater Energy, Fat, and Alcohol Intake.” Obesity Research 11:945–949.

15. Ruopeng, A. 2016. Weekend-Weekday Differences in Diet Among U.S. Adults, 2003– 2012. Annals of Epidemiolog y 26:57–65.

16. Ibid.

Using the exchange lists is a convenient method for designing a flexible meal plan that controls proportions of carbohydrate, protein, and fat intake. Because of their sim- ilar macronutrient composition, foods within each group can be exchanged or swapped with each other. Table 2.7 presents the number of food group choices in healthy,

Food Group 1,500 kcal 1,800 kcal 2,000 kcal 2,200 kcal 2,400 kcal

Starch 8 9 10 11 12

Fruit 3 4 4 4 5

Milk, low fat 2 2 3 3 3

Nonstarchy vegetables 4 5 6 6 7

Meat and meat substi- tutes, lean

3 5 5 6 7

Fat 5 6 6 7 7

TABLE 2.7 Number of Exchanges per Food Group per Day by Kilocalorie Intake

What Is the Exchange System? 57

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58 Chapter 2 | Tools for Healthy Eating

balanced diets of different kilocalorie levels that consist of 55 percent carbohydrate, 20 percent protein, and 25 percent fat. As you can see from the table, the higher the kilocalorie intake, the greater the number of choices from the exchange lists that are allowed. For complete exchange lists for meal planning, see Appendix C.

LO 2.5: THE TAKE-HOME MESSAGE The exchange system is a con- venient tool for creating meal plans based on the macronutrient content and total kilocalories of foods. The plan consists of six food groups: starch, fruit, milk, vegetables, meat, and fat. Foods within each group can be exchanged or swapped to add variety to meals and snacks.

What Information Is on the Food Label? LO 2.6 Identify the required components of a food label and Nutrition Facts

panel.

Do you pay close attention to the food labels of items you purchase at the supermar- ket? The information on labels can be tremendously useful when it comes to planning a healthy diet.

Food Labels Are Strictly Regulated by the FDA To help consumers make informed food choices, the Food and Drug Administration (FDA) regulates the labeling of all packaged foods in the United States. Since the 1930s, the FDA has mandated that every packaged food (Figure 2.8) be labeled with:

• The name of the food • The net weight, which is the weight of the food in the package, excluding the

weight of the package or packing material • The name and address of the manufacturer or distributor • A list of ingredients in descending order by weight, with the heaviest item

listed first

New labeling laws have been enacted to further benefit the consumer.20 In 1990, the Nutrition Labeling and Education Act (NLEA) began mandating that labels include uniform nutrition information, serving sizes, and specific criteria for health claims. Additional requirements for food labels have since been passed to require that labels now also show:

• A Nutrition Facts panel • Serving sizes that are uniform among similar products, which allows for easier

comparison shopping • An indication of how a serving of the food fits into an overall daily diet • Uniform definitions for descriptive label terms such as “light” and “fat free” • Health claims that are accurate and science based, if made about the food or

one of its nutrients • The presence of any of eight common allergens that might be present in

the food, including milk, eggs, fish, shellfish, tree nuts (cashews, walnuts, almonds, etc.), peanuts, wheat, and soybeans

Whereas raw fruits and vegetables and fresh fish typically don’t have a label, these foods fall under the FDA’s voluntary, point-of-purchase nutrition information program. Under the guidelines of this program, the nutrition information should be displayed in

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What Information Is on the Food Label? 59

close proximity to the foods.21 The nutrition information can be displayed as a label on the food or on store shelves, signs, posters, brochures, notebooks, leaflets, or a video near the food.22 Nutrition labeling must be provided for all meat and meat food products in the supermarket either on the label or at the point-of-purchase.23

Other nutrition information is sometimes available to consumers in the grocery aisle. Some supermarkets have initiated nutrition scoring systems that highlight the overall nutritional value of food products. This can also help the consumer make heathier choices.

The Nutrition Facts Panel Indicates Nutrient Values One area of the food label in particular, the Nutrition Facts panel, provides a nutri- tional snapshot of the food inside a package. By law the panel must list amounts of spe- cific nutrients. If an additional nutrient such as vitamin E or vitamin B12 has been added, or if the product makes a claim about a nutrient, then that nutrient must also be listed on the panel. The manufacturer can voluntarily list other nutrients, such as addi- tional vitamins and minerals. The majority of packaged foods contain this nutrition information.

Very few foods are exempt from carrying a Nutrition Facts panel on the label. Such foods include plain coffee and tea; some spices, flavorings, and other foods that don’t provide a significant amount of nutrients; bakery foods and other ready-to-eat foods that are prepared and sold in retail establishments; restaurant meals; and foods produced by small businesses (companies that have total sales of less than $500,000).24

In 2016, the FDA released a new Nutrition Facts panel. It was designed to reflect current research on the links between diet and chronic diseases and conditions, such as heart disease, stroke, type 2 diabetes, and obesity.

Because manufacturers have some time to phase in the new panel, you are likely to see a mix of the old panel and the new one on foods until this time. So let’s compare the old and new Nutrition Facts panels (Focus Figure 2.9).

Nutrition Facts panel Area on the food label that provides a list of specific nutrients obtained in one serving of the food.

▲ Figure 2.8 Labeling Requirements Mandated by the FDA The nutrition facts panel—such as the one on this box of Wheaties—can help consumers make informed food choices.

The name of the product must be displayed on the front label.

The net weight of the food in the box is located at the bottom of the package.

The ingredients must be listed in descending order by weight. Whole-grain wheat is the predominant ingredient in this cereal.

The Nutrition Facts panel lists standardized serving sizes and specific nutrients, and shows how a serving of the food fits into a healthy diet by stating its contribution to the percentage of the Daily Value for each nutrient.

The Guiding Stars in-store nutritional guidance system rates the nutrient density of foods. Foods that earn even one star are nutrient dense, but foods with three stars provide the optimal level of nutrients per kilocalories. Foods that do not meet the nutritional criteria do not display a star.

one

Good

two

Better

three

Best

Guiding Stars® Nutritious choices made simpleTM

®

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60 Chapter 2 | Tools for Healthy Eating

Head to Mastering Nutrition and watch a narrated video tour of this figure by author Joan Salge Blake.

Figure 2.9 The Nutrition Facts PanelFOCUS

• Daily Values are general reference values based on a 2,000 Calorie diet. • The %DV can tell you if a food is high or low in a nutrient or dietary substance. NEW • Daily Values are updated. • A shorter footnote that more clearly explains %DV is included. • The %DV for added sugar is included.

DAILY VALUES

• Vitamin A, vitamin C, calcium, and iron are required. • Other vitamins and minerals are voluntary. NEW • Vitamin D and potassium are required, in addition to calcium and iron. • Vitamins A and C are voluntary. • Actual amounts of each nutrient are listed as well as the %DV.

VITAMINS & MINERALS

NEW • Added sugars are listed.

ADDED SUGARS

• Serving sizes are standardized, making comparison shopping easier. NEW • Serving sizes are larger and bolder. • Serving sizes updated and more realistic.

SERVINGS

• Calories per serving and the number of servings in the package are listed. NEW • Calories are larger to stand out more. • “Calories from fat” is removed.

CALORIES

The U.S. Food and Drug Administration (FDA) has made changes to the 20-year-old nutrition labels on packaged foods. The changes to the nutrition label provide information to help compare products and make healthy food choices.

Nutrition Facts Serving Size 2/3 cup (55 g) Servings Per Container About 8

Amount Per Serving

Total Fat Sat Fat Cholesterol Sodium Total Carbohydrate Dietary Fiber

Calories: 2,000 2,500

Less than 65 g 80 g Less than 20 g 25 g Less than 300 mg 300 mg Less than 2,400 mg 2,400 mg 300 g 375 g 25 g 30 g

Calories 230 Calories from Fat 72

% Daily Value* Total Fat 8 g 12% Saturated Fat 1 g 5% Trans Fat 0 g Cholesterol 0 mg 0% Sodium 160 mg 7% Total Carbohydrate 37 g 12% Dietary Fiber 4 g 16% Sugars 1 g Protein 3 g

Vitamin A 10% Vitamin C 8% Calcium 20% Iron 45% * Percent Daily Values are based on a 2,000

calorie diet. Your daily value may be higher or lower depending on your calorie needs.

OLD LABEL NEW LABEL

Nutrition Facts 2/3 cup (55g)

10%

5%

0%

7%

13%

14%

10%

20%

45%

6%

20%

160mg

8gTotal Fat

Saturated Fat 1g

Trans Fat 0g

Cholesterol 0mg Sodium

Total Carbohydrate 37g

Dietary Fiber 4g

Total Sugars 12g

Includes 10g Added Sugars Protein 3g

Vitamin D 2mcg

Calcium 260mg

Iron 8mg

Potassium 235mg

% Daily Value*

The % Daily Value (DV) tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

*

8 servings per container Serving size

Calories 230 Amount per serving

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What Information Is on the Food Label? 61

The top band of the Nutrition Facts panel indicates the serving size. In the new panel, this is in boldface type to help consumers see it more readily. By law, the serving size must be listed both by weight in grams and in common household measures, such as cups and ounces. Serving sizes are standardized among similar food products, making it easier to compare brands. On the new panel, the serving sizes for some foods have been updated to mirror the amounts that people actually eat. For example, while 1⁄2 cup of ice cream was previously the standard serving, it is now going to be 2⁄3 cup, an amount that people will likely scoop into a bowl.

The rest of the information on the panel is based on the listed serving size of the food. For example, if a serving were 1 cup, but you ate 2 cups, you would need to double the nutrient information on the panel. The servings-per-container information is useful for portion control.

Listed below the serving size is the kilocalories per serving. Notice that the new panel gives this information in large boldface type. Below this is a list of the nutrients that should be limited or increased in the diet. Americans typically eat too much fat, including saturated fat and trans fat, and too much sodium. In contrast, they tend to fall short in dietary fiber, vitamin D, and calcium, iron, and potassium. These are on the panel to remind you to choose foods rich in these substances. The old panel required manufacturers to list vitamins A and C, but these are no longer considered nutrients of concern; thus, their presence on the panel is now voluntary. A food manufacturer also may voluntarily list other nutrients, such as vitamin B12 or folate. Overall, the Nutrition Facts panel can be your best shopping guide to foods that are low in the nutrients you want to limit, such as saturated fat, and high in the nutrients that you need to eat in higher amounts, such as potassium.

The new panel identifies added sugars, indented as a subcategory of “Total Sug- ars.” Recall from Chapter 1 that added sugars are not naturally occurring, but added during the manufacturing of the food. It is difficult for many Americans to meet their nutrient needs while staying within their kilocalorie limits for the day if their diets are high in added sugars. Americans are currently consuming approximately 13 percent of their daily kilocalories from added sugars. The current recommendation is to consume less than 10 percent of kilocalories from added sugars daily.

Are you wondering what determines if a food contains a “high” or “low” amount of a specific nutrient? That’s where the percent Daily Values come into play.

The Percent Daily Values Help You Compare Packaged Foods Unlike the DRIs, which are precise recommended amounts of each nutrient that you should eat, the percent Daily Values (%DVs) listed on the Nutrition Facts panel are general reference levels for the nutrients listed on the food label. The %DVs give an idea of how the nutrients in the foods you buy fit into your overall diet.

For example, if calcium is listed at 10 percent, a serving of that food provides 10 percent of most adults’ daily requirement for calcium. Because the %DVs on the food label are based on a 2,000-kilocalorie diet, if you need more or fewer than 2,000 kilocalories daily, some of your %DV numbers may be higher or lower than those listed on the Nutrition Facts panel.

There are no %DVs listed on the label for trans fat, total sugars, and protein. You should consume as little trans fat as possible. Notice that the new panel identifies a %DV for added sugars. Although there are reference values for protein, consuming adequate amounts of protein isn’t a health concern for most Americans over age 4, so listing the %DV for this nutrient isn’t warranted. The %DV for protein is listed on products being marketed for children under the age of 4, such as baby food, and when a claim is made about the food, such as that it is “high in protein.”25

serving size Recommended portion of food that is used as a standard reference on food labels.

percent Daily Values (%DVs) Reference val- ues developed by the Food and Drug Admin- istration and used on the Nutrition Facts panel to describe the percentage of a daily nutrient intake provided in one serving of the food.

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62 Chapter 2 | Tools for Healthy Eating

If a serving provides 20 percent or more of the %DV, it is considered high in that nutrient. For example, a serving of the granola shown in Focus Figure 2.9 is high in cal- cium and iron (a healthy attribute). If a nutrient provides 5 percent or less of the %DV, it is considered low in that nutrient. A serving of this granola is low in saturated fat (another healthy attribute).

Lastly, both panels provide a footnote at the bottom of the label that explains the meaning of the %DVs. However, the old panel provided examples of %DVs for a 2,000-kilocalorie and 2,500-kilocalorie diet. These examples were eliminated from the new panel, and the explanation was revised to improve clarity.

The table inside the back cover of this book identifies the %DVs on the footnote of the Nutrition Facts panel. These are regularly updated to reflect the latest scientific evidence. For example, the %DV for fiber has increased from 25 grams to 28 grams, whereas the %DV for sodium has decreased from 2,400 milligrams to 2,300 milligrams.

Label Claims Can Reveal Potential Health Benefits In the 1980s, the Kellogg Company ran an ad campaign for its fiber-rich All Bran cereal reminding the public of the National Cancer Institute’s recommendation to eat low-fat, high-fiber foods, fresh fruits, and vegetables to maintain a healthy weight. According to the FDA, sales of high-fiber cereals increased over 35 percent within a year.26

For decades, manufacturers realized that putting nutrition and health claims on labels was effective in influencing consumer purchases. Supermarket shelves were soon crowded with products boasting various claims.

The FDA mandates that all claims on labels follow strict guidelines. Currently, the FDA allows the use of three types of claims on food products: (1) nutrient content claims, (2) health claims, and (3) structure/function claims. All foods displaying these claims on the label must meet specified criteria.

Nutrient Content Claims A food product can make a claim about the amount of a nutrient it contains (or doesn’t contain) by using descriptive terms such as free (fat-free yogurt), high (high-fiber crackers), low

(low saturated fat cereal), reduced (reduced-sodium soup), and extra lean (extra lean ground beef) as long as it meets the strict criteria designated by the FDA. These terms can help iden- tify at a glance the food items that best meet your needs. For instance, if you want to decrease or limit the amount of sodium in your diet, you could look for low-sodium claims on labels.

Look at the labels of the canned soups in Figure 2.10. Note that the “low-sodium” version of the chicken soup cannot contain more than 140 milligrams of sodium per serving. In contrast, the soup with the term “less sodium” on the label contains 450 milligrams of sodium per serv- ing, which is at least 25 percent less sodium than the regular variety. The can of classic chicken soup contains almost 900 milligrams for a serving, which is likely the same or even more sodium than the average American consumes at din- ner. Table 2.8 provides some of the most common nutrient claims on food labels and the specific criteria that each claim must meet as mandated by the FDA.

Health Claims Suppose you are sitting at your kitchen table eating a bowl of breakfast cereal. You may notice a claim on the front of the

▲ Figure 2.10 Soup’s On! Nutrient claims on the food label must conform to strict criteria.

Because this can of Campbell’s Chicken Noodle soup displays the “low sodium” nutrient claim, it can’t provide more than 140 milligrams of sodium in a serving.

a This can of Campbell’s Chicken Noodle soup has more than 25 percent less sodium than the classic version, so the term “less” can be displayed on its label.

b The classic variety of Campbell’s Chicken Noodle soup has the most sodium per serving.

c

a b

c

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What Information Is on the Food Label? 63

box that states: “The soluble fiber in oats, as part of a heart-healthy diet, can help lower your cholesterol.” Do you recognize this as a health claim that links oatmeal with better heart health?

A health claim (Figure 2.11) must contain two important components: (1) a food or a dietary compound, such as fiber, and (2) a corresponding disease or health-related condition that is associated with the substance.27

In the cereal example, the soluble fiber (the dietary compound) that naturally occurs in oats has been shown to lower blood cholesterol levels (the corresponding health- related condition), which can help reduce the risk of heart disease.

There are three types of health claims: (1) authorized health claims, (2) health claims based on authoritative statements, and (3) qualified health claims. The differences between them lie in the amount of supporting research and agreement among scientists about the strength of the relationship between the food or dietary ingredient and the disease or con- dition. See Table 2.9 for a definition and examples of each type of health claim.

Structure/Function Claims The last type of label claim is the structure/function claim, which describes how a nutri- ent or dietary compound affects the structure or function of the human body.28 The claims “Calcium builds strong bones” and “Fiber maintains bowel regularity” are exam- ples of structure/function claims.29 Structure/function claims cannot state that the nutri- ent or dietary compound can be used to treat a disease or a condition.

Nutrient Free Low Reduced/Less Light

Kilocalories 65 kilocalories (kcal) per serving

640 kcal per serving At least 25% fewer kcal per serving

If the food contains 50% or more of its kcal from fat, then the fat must be reduced

Fat 60.5 grams (g) per serving 63 g per serving At least 25% less fat per serving Same as above Saturated fat

60.5 g per serving 61 g per serving At least 25% less saturated fat per serving

N/A

Cholesterol 62 milligrams (mg) per serving

620 mg per serving At least 25% less cholesterol per serving

N/A

Sodium 65 mg per serving 6140 mg per serving At least 25% less sodium per serving

If the sodium is reduced by at least 50% per serving

Sugars 60.5 g N/A At least 25% less sugar per serving

N/A

Other Labeling Terms

Term Definition

“High,” “Rich in,” or “Excellent source of” The food contains 20% or more of the DV of the nutrient in a serving. Can be used to describe protein, vitamins, minerals, fiber, or potassium.

“Good source of” A serving of the food provides 10–19% of the DV of the nutrient. Can be used to describe protein, vitamins, minerals, fiber, or potassium.

“More,” “Added,” “Extra,” or “Plus” A serving of the food provides 10% of the DV. Can only be used to describe vitamins, minerals, protein, fiber, and potassium.

“Lean” Can be used on seafood and meat that contains less than 10 g of fat, 4.5 g or less of saturated fat, and less than 95 mg of cholesterol per serving.

“Extra lean” Can be used on seafood and meat that contains less than 5 g of fat, less than 2 g of saturated fat, and less than 95 mg of cholesterol per serving.

“Healthy” Low in fat and saturated fat; limited in cholesterol content; sodium content can’t exceed 360 mg for individual foods or 480 for meal-type foods; contains 10% of the DV of one or more of vitamins A and C, iron, calcium, protein, or fiber.

Note: N/A = not applicable.

TABLE 2.8 Nutrient Content Claims on Food Labels

▲ Figure 2.11 An Authorized Health Claim The text on this box of Cheerios is an authorized health claim stating that soluble fiber reduces the risk of heart disease.

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64 Chapter 2 | Tools for Healthy Eating

Structure/function claims can be made on both foods and dietary supplements. Unlike the health claims, they don’t need to be preapproved by the FDA. They do need to be truthful and not misleading, but the manufacturer is responsible for making sure that the claims are accurate.

Structure/function claims can be a source of confusion. Shoppers can easily fall into the trap of assuming that one brand of a product with a structure/function claim on its label is superior to another product without the claim. For instance, a yogurt that says “Calcium builds strong bones” on its label may be identical to another yogurt without the flashy label claim. The consumer has to understand that the yogurt with the claim is not superior to the yogurt without it.

Type of Claim Definition Examples

Authorized health claims (well established)

Claims are based on a well-established relationship between the food or compound and the health benefit. Food manufacturers must submit a petition to the FDA and provide the scientific research that backs up the claim. If there is significant agreement in the supporting research and a consensus among numerous scien- tists and experts in the field that there is a relationship between the food or dietary ingredient and the disease or health condition, the FDA will allow an authorized health claim. Specified wording must be used.

The FDA has approved 12 authorized health claims.

1. Calcium and osteoporosis 2. Sodium and hypertension 3. Dietary fat and cancer 4. Dietary saturated fat and cholesterol and risk of

coronary heart disease 5. Fiber-containing grain products, fruits, and veg-

etables and cancer 6. Fruits, vegetables, and grain products that con-

tain fiber, particularly soluble fiber, and the risk of coronary heart disease

7. Fruits and vegetables and cancer 8. Folate and neural tube defects 9. Dietary sugar, alcohol, and dental caries

10. Soluble fiber from certain foods and risk of coronary heart disease

11. Soy protein and risk of coronary heart disease 12. Plant sterol/stanol esters and risk of coronary

heart disease

Health claims based on authoritative statements (well established)

Claims based on statements made by a U.S. govern- ment agency, such as the Centers for Disease Control and Prevention (CDC) and the National Institutes of Health (NIH). If the FDA approves a claim submitted by the manu- facturer, the wording of the claim must include “may,” as in “whole grains may help reduce the risk of heart disease,” to illustrate that other factors in addition to the food or dietary ingredient may play a role in the disease or condition. This type of health claim can only be used on food and cannot be used on dietary supplements.

• Whole-grain foods and risk of heart disease and certain cancers

• Potassium and the risk of high blood pressure • Substitution of saturated fat in the diet with

unsaturated fat and reduced risk of heart disease

Qualified health claims (less well established)

Claims based on evidence that is still emerging. How- ever, the current evidence to support the claim is greater than the evidence suggesting that the claim isn’t valid. These claims are allowed in order to expedite the com- munication of potential beneficial health information to the public. They must be accompanied by the statement “the evidence to support the claim is limited or not con- clusive” or “some scientific evidence suggests. . . .” Many experts, including the Academy of Nutrition and Dietetics, don’t support this type of health claim, as it is based on emerging evidence. Qualified health claims can be used on dietary supple- ments if approved by the FDA.

• Selenium and cancer • Antioxidant vitamins and cancer • Nuts and heart disease • Omega-3 fatty acids and coronary heart disease • B vitamins and vascular disease • Monounsaturated fatty acids from olive oil and

coronary heart disease • Walnuts and heart disease • Psyllium husk and diabetes

TABLE 2.9 Health Claims on Food Labels

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Portion Distortion 65

Dietary supplements that use structure/function claims must display a disclaimer on the label stating that the FDA did not evaluate the claim and that the dietary supplement is not intended to “diagnose, treat, cure, or prevent any disease.” Manufacturers of foods bearing structure/function claims do not have to display this disclaimer on the label.

Although keeping the types of health claims and the structure/function claims straight can be challenging, here’s one way to remember them: Authorized health claims and health claims based on authoritative statements are the strongest, as they are based on years of accumulated research or an authoritative statement. Qualified health claims are made on potentially healthful foods or dietary ingredients but because the evidence is still emerging, the claim has to be “qualified” as such. All health claims provide information on how the food or dietary ingredient can help reduce your risk of a condition or a disease.

Structure/function claims are the weakest claims, as they are just statements or facts about the role the nutrient or dietary ingredient plays in the body. They can’t claim how the food or dietary ingredient lowers the risk of developing a chronic disease such as heart disease or cancer. In general, label claims with less established scientific evidence behind them have the weakest wording.

LO 2.6: THE TAKE-HOME MESSAGE The FDA regulates the labeling on all packaged foods. Every food label must contain the name of the food, its net weight, the name and address of the manufacturer or distributor, a list of ingredients, and a Nutrition Facts panel containing standardized nutrition information. The FDA allows the use of nutrient content claims, health claims, and structure/function claims on food labels. Any foods or dietary supplements displaying these label claims must meet specified criteria and the claims must be truthful.

HEALTHCONNECTION

Portion distortion, or perceiving larger portions of food as appropriate sizes, may be contributing to obesity. These larger-than-recommended portion sizes, which are viewed as typical by Americans today, add kilocalories to our diets and may contribute to weight gain.

Portion versus Serving Size: What’s the Difference? The USDA defines a portion as the amount of food eaten at one sitting. In

contrast, a serving size (a term that’s used only on food labels) is a stan- dard amount of food for which the nutrient composi- tion is presented. We can illustrate the difference with a food that people often pile on their plates, such as spa- ghetti. A generous

Portion Distortion LO 2.7 Compare the terms portion

and serving size and summarize the health benefits of controlling your portions.

The portion of pasta (left) that Americans typically eat is larger than the serving size indicated on food labels (right).

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66 Chapter 2 | Tools for Healthy Eating

HEALTHCONNECTION (CONTINUED)

up over the past few decades. If you were to measure your grandmother’s favorite dinner plates, they would likely be much smaller, about 9 inches in diameter, than the plates in your cupboard, which probably measure closer to 11.5 inches across. The bigger the plate, the more food you are likely to put on it. Furthermore, the larger the portion we put on that plate, the less accurate we are in our estimate of how many kilocalories we’re consuming.

Health Effects of Increased Portion Size Research has shown that an increase in the portion sizes of typical foods can lead to increased energy intake and weight gain.34,35,36 As body weight increases, the risk of developing chronic diseases— including cardiovascular disease, diabetes, joint problems, and some cancers—also increases. Moreover, eating larger por- tions of foods high in added sugars and saturated fats not only increases your daily kilocalorie intake but can also decrease the amount of nutrients you consume overall. For example, eating a

helping of cooked spaghetti that spills over the edge of a plate is probably equal to about 3 cups. According to MyPlate, a standard serving size of pasta is 1⁄2 cup.30 A portion of 3 cups of cooked pasta is therefore six servings, which contains more than 600 kilocalories!

How Have Portion Sizes Changed? If your great-grandmother treated herself to a Hershey’s chocolate bar when it was first introduced, at the beginning of the last century, she would have purchased a bar weighing about 0.6 ounce. Today the same milk chocolate bar is sold in 0.75-, 1.6-, 2.6-, 4.0-, 7.0-, and 8.0-ounce weights. When McDonald’s first intro- duced French fries in 1954, the standard serving weighed 2.4 ounces. Although a small 2.4-ounce size is still on the menu, you can also choose the medium French fries weighing 5.3 ounces or the large at 6.3 ounces. Twenty years ago, a cup of coffee was 8 ounces and just 45 kilocalories with added milk and sugar. Today, consum- ers enjoy 16-ounce lattes on their way to work, to the tune of 350 kilocalories.31 As you can see, portion sizes have changed across the menu.

The restaurant industry has appealed to Americans’ interest in getting more food for less money with larger portion sizes at relatively low costs. Americans eat out more often than they did in the past and are often offered a wide variety of inexpensive choices sold in portion sizes that typically exceed the standards defined in MyPlate.32 Most people are unaware of the changes in their portion sizes. And even when they are aware, they don’t necessarily change their behavior. Recent studies show that posting the kilocalorie content of menu items on sign boards or on menus has little impact on consumers’ behavior.33 Though getting more food for the money may be beneficial on the wallet, the health costs may be higher than Americans realize.

In addition to restaurant and packaged foods, home-cooked meals have also bulked

large portion of red meat as an entrée will increase the total fat, saturated fat, and cholesterol you consume. Instead, if the meat portion is limited and the plate is filled with large portions of vegetables, fruits, and a reasonable portion of whole grains, the result is an increase in the vitamins, minerals, phytochemicals, and dietary fiber in the meal and a decrease in the total kilocalories.

Tips for Controlling Portion Size Unfortunately, many of us frequently underestimate the portion sizes we put on our plates or in our glasses and there- fore overeat.37 One easy way to tell if you are helping yourself to too much of a food is to use a visual that represents a standard serving size of the food, such as a cup of vegetables, three ounces of meat, or 1 tablespoon of salad dress- ing. Having a food scale available is not always possible. Instead, use an everyday item that you always have with you—your hand—to visualize the correct portion sizes (Figure 2.12). This provides an easy

▲ Figure 2.12 What’s a Portion Size? Eat with Your Hands! Your hands can help you estimate the appropriate portion size of foods.

a c

d

A woman’s palm is the size of approximately 3 ounces of cooked meat, chicken, or fish

b

A woman’s fist is the size of about 1 cup (a man’s fist is the size of about 2 cups)

The “O” made by a woman’s thumb and forefinger is the size of about 1 tablespoon of vegetable oil.

The tip of the finger is about 1 teaspoon of margarine or butter

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HEALTHCONNECTION (CONTINUED)

Portion Distortion 67

LO 2.7: THE TAKE-HOME MESSAGE A portion size is defined as the amount of food eaten at one sitting, whereas a serving size is the standard amount of food for nutrient comparison used on nutrient labels. Portion sizes have continued to increase over the last few decades, and increased portion sizes are thought to have contributed to America’s incidence of overweight and obesity. The risk of developing chronic diseases, including cardiovascular disease, diabetes, joint problems, and even some cancers, increases as body weight increases. Measure your foods until you recognize a healthy portion size, use smaller glasses and plates, divide larger packages of food into indi- vidual portion sizes, and share meals when eating out to control portion sizes.

When You Are . . . Do This

At Home • Measure your food until you develop an “eye” for correct portion sizes, and check your measurements now and then to make sure they haven’t crept up.

• Use smaller plates so portions appear larger. • Plate your food at the counter before sitting down at the table. • Store leftover foods in portion-controlled containers. • Don’t eat snacks directly from the box or bag; measure a portion first, then

eat only that amount. • Cook smaller quantities of food so you don’t pick at the leftovers. • Keep tempting foods, such as sweets and chips, out of sight.

Eating Out • Ask for half orders when available. • Order an appetizer as your entrée. • Don’t be compelled to “clean your plate”; stop eating when you’re full and

take the rest home.

Buying Groceries • Divide a package of snacks into individual portion sizes and consume only one portion at any one sitting.

• Be aware of the number of servings in a package; read the labels. • Buy foods that are already divided into portion sizes, such as 1 oz sliced

cheese or lunch meat. • Avoid “mini” sizes of crackers, cookies, etc.; just because they’re small

doesn’t mean you can eat the whole box!

TABLE 2.10 Controlling Portion Sizes

way to approximate how much you are consuming.

Other steps that can help reduce over- sized portions include buying smaller or single-portion packages of foods or divid- ing larger packages into individual portion sizes. In restaurants, order one meal to share with your companion, or split the food in half and take the other half home. In your cupboard, replace larger glasses and plates with smaller versions. Table 2.10 provides further tips for controlling your portion sizes at home and elsewhere.

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68 Chapter 2 | Tools for Healthy Eating

LO 2.2 Dietary Reference Intakes Are Reference Values for Each Nutrient The Dietary Reference Intakes (DRIs) are specific reference values, based on age and gender, that express the quantities of the essential nutrients needed daily. The DRIs are designed to prevent nutrient deficiencies, maintain good health, prevent chronic diseases, and avoid unhealthy excesses. The DRIs consist of the Estimated Average Requirement, Recommended Dietary Allowance, Adequate Intake, Tolerable Upper Intake Level, and the Acceptable Macronutrient Distribution Ranges. The Estimate Energy Requirement indicates how much energy an individual needs based on age, gender, and activity level.

LO 2.1 Healthy Eating Is Based on Five Key Principles Healthy eating involves the key principles of balance, variety, and moderation. Foods should also be nutrient dense to provide adequate nutrition, but low in energy density to prevent unwanted weight gain.

Visual Chapter Summary

LO 2.3 Dietary Guidelines for Americans Are Recommendations to Lower Risk of Disease The Dietary Guidelines for Americans are published every 5 years by the USDA and HHS to provide Americans with current, research-based nutrition and physical activity recommendations. The current DGAs emphasize following a healthy eating pattern such as a Mediterranean-style diet, a vegetarian diet, or another diet rich in fruits, vegetables, and whole grains. Following the DGAs can help improve the quality of the diet and lower the risk of obesity and cer- tain chronic diseases.

Increased risk of toxicity

Increasing amount of nutrient

N um

be r o

f i nd

iv id

ua ls

in a

s pe

ci fic

ag

e an

d ge

nd er

g ro

up

EAR (Meets nutrient

needs for 50% of individuals)

RDA (Meets nutrient

needs for 97–98% of individuals)

UL

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LO 2.4 MyPlate Includes an Icon for Healthy Eating and an Accompanying Website MyPlate is an icon that serves as a reminder for healthy eat- ing. It helps consumers plan a plant-based diet that meets the recommendations of the DGAs and the DRIs for the essential nutrients. There are five food groups: fruits, vegetables, grains, protein, and dairy. Oils are not shown on MyPlate because they are not a food group but are an important part of a healthy diet.

LO 2.5 The Exchange System Is Based on the Macronutrient Content of Foods Exchange lists group foods according to their carbohydrate, pro- tein, fat, and kilocalorie content while providing specific portion sizes. Using the exchange lists for meal planning is a convenient method for developing flexible meal plans.

LO 2.6 The Required Components of Food Labels Provide Important Nutrition Information The FDA regulates the information found on food labels. The Nutrition Facts panel must list the serving size of the food and the corresponding amount of kilocalories, fat, saturated fat, trans fat, cholesterol, sodium, sugars, added sugars, dietary fiber, protein, vitamin D, and calcium, iron, and potassium. The percent Daily Values are reference lev- els of intakes for the nutrients listed on the food label.

A food label can carry a nutrient content claim using descriptive terms such as free, high, and extra lean, as long as it meets strict FDA criteria. Health claims can also be used on food labels. These contain a food compound or a dietary ingredient and an associated disease or health-related con- dition. Structure/function claims describe how a food or dietary compound affects the structure or function of the body, and are not subject to FDA regulation.

Nutrition Facts 2/3 cup (55g)

10%

5%

0%

7%

13%

14%

10%

20%

45%

6%

20%

160mg

8gTotal Fat

Saturated Fat 1g

Trans Fat 0g

Cholesterol 0mg Sodium

Total Carbohydrate 37g

Dietary Fiber 4g

Total Sugars 12g

Includes 10g Added Sugars Protein 3g

Vitamin D 2mcg

Calcium 260mg

Iron 8mg

Potassium 235mg

% Daily Value*

The % Daily Value (DV) tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.

*

8 servings per container Serving size

Calories 230 Amount per serving

Visual Chapter Summary 69

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70 Chapter 2 | Tools for Healthy Eating

LO 2.7 Controlling Portion Size Can Reduce the Risk of Weight Gain and Chronic Disease A portion size is the amount of food eaten at one sitting, regardless of the standard serving size printed on food labels. Larger portion sizes can lead to increased energy intake and weight gain. Over time weight gain can increase your risk for cardiovascu- lar disease, diabetes, joint problems, and certain cancers. Learn to recognize a healthy portion size, use smaller plates and glassware, and divide large portions into individ- ual portions to improve healthy eating and prevent weight gain.

Size equivalent of 3 ounces of meat

Size equivalent of 1 cup

Size equivalent of 1 tablespoon

Size equivalent of 1 teaspoon

Terms to Know ■■ balance ■■ vary ■■ moderate ■■ nutrient density ■■ energy density ■■ portion ■■ satiety ■■ Dietary Reference Intakes (DRIs) ■■ nutrient requirements ■■ Estimated Average Requirement (EAR) ■■ Recommended Dietary

Allowance (RDA) ■■ Adequate Intake (AI) ■■ Tolerable Upper Intake Level (UL) ■■ toxicity ■■ Acceptable Macronutrient Distribution

Ranges (AMDRs) ■■ Estimated Energy Requirement (EER) ■■ Dietary Guidelines for Americans ■■ MyPlate ■■ proportionality ■■ exchange lists ■■ Nutrition Facts panel ■■ serving size ■■ percent Daily Values (%DVs)

Mastering Nutrition Visit the Study Area in Mastering Nutrition to hear an MP3 chapter summary.

Check Your Understanding LO2.1 1. Nutrient-dense foods

a. contain an equal balance of carbohydrates, proteins, and fats.

b. are high in nutrients and lower in kilocalories.

c. have a nutrition label. d. have greater weight than

volume.

LO2.1 2. Which of the following foods is the most nutrient dense? a. An orange ice pop b. An orange c. Orange-flavored soda d. Orange sherbet

LO2.2 3. The Dietary Reference Intakes (DRIs) are reference values for nutrients and are designed to a. only prevent nutritional

deficiencies. b. provide a general range of

nutrient needs. c. prevent nutritional deficien-

cies and toxicities and maintain good health.

d. apply only to infants and children.

LO2.2 4. An Estimated Average Requirement (EAR) is a. the estimated amount of a

nutrient that should be con- sumed daily to be healthy.

b. the amount of a nutrient that meets the average needs of 50 percent of individuals in a specific age and gender group.

c. the maximum safe amount of a nutrient that should be con- sumed daily.

d. the amount of a nutrient that meets the needs of 99 percent of the population.

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Answers to True or False? 71

LO2.3 5. The Dietary Guidelines for Americans recommend that you a. limit the amount of saturated

fat and added sugars in your diet.

b. stop smoking and walk daily. c. sleep 8 hours a night and jog

every other day. d. maintain a kilocalorie balance

over time and stop smoking. LO2.4 6. Which of the following are

the food groups in MyPlate? a. Grains, vegetables, dairy,

sweets, and protein b. Grains, fruits, alcohol, sweets,

and proteins c. Grains, vegetables, fruits,

dairy, and protein d. Grains, vegetables, oils, dairy,

and proteins LO 2.5 7. The exchange system places

foods in groups based on their carbohydrate, fat, and protein content. a. True b. False

LO 2.6 8. By law, which of the follow- ing must be listed on the new Nutrition Facts panel? a. %DV for kilocalories, total

sugars, and protein b. Saturated fat, vitamin A, and

vitamin C c. Kilocalories, added sugars,

and potassium per serving d. Vitamin A, vitamin E, and

folate LO 2.6 9. A yogurt that states that a

serving provides 30 percent of the percent Daily Value (%DV) for calcium contains a ________ amount of calcium. a. high b. medium c. low d. negligible

LO 2.10 10. At his campus dining hall, Hamid serves himself—and eats—two heaping ladles of rice. This amount is a. a standard serving size. b. Hamid’s serving size. c. a standard portion. d. Hamid’s portion.

Answers 1. (b) Nutrient-dense foods are high in

nutrients, such as vitamins and min- erals, but low in energy (kilocalories).

2. (b) Though an orange ice pop or orange sherbet may be a refreshing treat on a hot day, the orange is by far the most nutrient-dense food among these choices. The orange- flavored soda is a sugary drink.

3. (c) The DRIs recommend the amount of nutrients needed to prevent deficiencies, maintain good health, and avoid toxicities. Values are provided for populations ranging from infants to older adults.

4. (b) The EAR is the amount of a nutrient that would meet the needs of half of the individuals in a spe- cific age and gender group. The EAR is used to obtain the Recommended Dietary Allowance (RDA), which is the amount of a nutrient that should be consumed daily to maintain good health. The Tolerable Upper Intake Level (UL) is the maximum amount of a nutrient that can be consumed on a regular basis that is unlikely to cause harm.

5. (a) The Dietary Guidelines for Ameri- cans recommend that you limit the amount of saturated fat and added sugars in your diet. Walking or jogging are wonderful ways to be physically active. Though the Dietary Guidelines do not specifically address stopping smoking, this is a habit worth kicking. Sleeping 8 hours a night isn’t mentioned in the Dietary Guidelines but is another beneficial lifestyle habit.

6. (c) Grains, vegetables, fruits, dairy, and protein are the five basic food groups in MyPlate. Plant and fish oils are healthful, but do not constitute a MyPlate food group. Sweets and alcohol are not food groups and should be limited in the diet.

7. (a) True. The exchange system lists the foods in groupings according to their carbohydrate, protein, and fat composition and provides specific portion sizes for each food.

8. (c) The new Nutrition Facts panel must indicate the amounts per serv- ing of kilocalories, added sugars, and potassium. Vitamins A, C, E, and folate do not have to be listed unless they have been added to the food and/or the product makes a claim about them on the label. The panel does not indicate the %DV for kilocalories, total sugars, or protein; however, the %DV for added sugars is listed.

9. (a) Foods that provide 20 percent or more of the %DV for a nutrient are considered “high” in that nutri- ent. If the label states that a serving contains 5 percent or less of the %DV, it is considered “low” in that nutrient.

10. (d) A portion is the amount of food eaten at one sitting; thus, the two heaping ladles of rice is Hamid’s portion. There are no standardized portions. A serving size is a standard amount of food for which the nutri- ent composition is presented. It is a term used on food labels.

Answers to True or False? 1. False. Having a balanced diet means

not eating too much of any one food. 2. False. Because consuming too much

of some essential nutrients can be harmful, the Tolerable Upper Intake Level (UL) of the DRIs was estab- lished for many nutrients.

3. True. The Dietary Reference Intakes are specific reference values for each nutrient according to age, gender, and life stage. They were established to prevent nutrient deficiencies and toxicities and to maintain good health and reduce the risk of devel- oping chronic diseases.

4. True. These Dietary Guidelines for Americans are the latest recommenda- tions for nutrition and physical activ- ity for Americans over the age of 2.

5. True. The five food groups that make up the MyPlate recommendations are grains, vegetables, fruits, dairy, and protein.

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72 Chapter 2 | Tools for Healthy Eating

6. False. Oils are not considered a food group but you should consume some daily for good health.

7. True. Exchange lists allow you to swap foods within each food group while still controlling the amount of carbohydrate, protein, fat, and kilo- calories you ingest.

8. False. A nutrient content claim uses descriptive terms (such as low sodium or fat free) to make a claim about the amount of a nutrient a serving of the food contains (or doesn’t contain). Specific terms approved by the FDA must be used.

9. True. The FDA requires that all pack- aged food items be labeled with spe- cific information.

10. False. A portion of food is the amount of food you choose to eat. A standard serving size is defined by the USDA as a standard amount used on food labels.

Web Resources ■■ For more tips and resources for

MyPlate, visit www.ChooseMyPlate .gov.

■■ For details on the latest Dietary Guidelines for Americans, visit Department of Health and Human Services https://health. gov/dietaryguidelines/.

■■ For more on food labels, visit www .fda.gov.

References 1. Freeland-Graves, J. H., and S. Nitzke. 2013.

Position of the Academy of Nutrition and Dietetics: Total Diet Approach to Healthy Eating. Journal of the Academy of Nutrition and Dietetics. 113(2):307–317.

2. Ibid. 3. Produce for Better Health Foundation.

Fruits and Vegetables—More Matters. Available at www.fruitsandveggiesmorematters.org. Accessed February 2017.

4. U.S. Department of Health and Human Ser- vices and U.S. Department of Agriculture. 2015–2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at http://health.gov/dietaryguidelines/2015/ guidelines/. Accessed February 2017.

5. Stelmach-Mardas, Marta, Tomasz Rodacki, et al. 2016. Link Between Food Energy Density and Body Weight Changes in Obese Adults. Nutrients 8(4):229.

6. Ibid. 7. Eldridge, Johanna D., Carol M. Devine, et al.

2016. Environmental Influences on Small Eating Behavior Change to Promote Weight

Loss among Black and Hispanic Populations. Appetite 96:129–137.

8. Lau, D. C., and H. Teoh. 2013. Benefits of Modest Weight Loss on the Management of Type 2 Diabetes Mellitus. Canadian Journal of Diabetes 37(2):128–134.

9. Williams, R. A., L. S. Roe, et al. 2013. Comparison of Three Methods to Reduce Energy Density. Effects on Energy Density Intake. Appetite 66:75–83.

10. Institute of Medicine. 2003. Dietary Reference Intakes: Applications in Dietary Planning. Washington, DC: The National Academies Press. Updated 2013. Available at http://fnic.nal.usda.gov. Accessed February 2017.

11. Ibid. 12. Ibid. 13. Ibid. 14. Mowry, James B., Daniel A. Spyker, et al.

2015. 2014 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 32nd Annual Report. Clinical Toxicology 53, Iss. 10.

15. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015.

16. Farazo, E. 1999. America’s Eating Habits: Changes and Consequences. Updated 2012. Available at www.ers.usda.gov. Accessed February 2017.

17. Lee, P. R. 1978. Nutrition Policy: From Neglect and Uncertainty to Debate and Action. Journal of the American Dietetic Associa- tion 72:581–588.

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References 73

18. Report of the DGAC on the Dietary Guidelines for Americans, 2015. 2015. Available at https://health.gov/ dietaryguidelines/2015-scientific-report/ PDFs/Scientific-Report-of-the-2015- Dietary-Guidelines-Advisory-Committee. pdf. Accessed February 2017.

19. U.S. Department of Health and Human Ser- vices and U.S. Department of Agriculture. 2015–2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at http://health.gov/dietaryguidelines/2015/ guidelines/. Accessed February 2017.

20. Food and Drug Administration. Revised 2013. A Food Labeling Guide. Available at www.fda.gov. Accessed February 2017.

21. Food and Drug Administration. 2016. CFR – Code of Federal Regulations Title 21. Available at www.accessdata.fda.gov/ scripts/cdrh/cfdocs/cfcfr/CFRSearch .cfm?fr=101.45. Accessed February 2017.

22. Ibid. 23. USDA 2016. Nutrition Labeling Informa-

tion. Available at https://www.fsis.usda.gov/ wps/portal/fsis/topics/regulatory-compli- ance/labeling/labeling-policies/nutrition- labeling-policies/nutrition-labeling. Accessed February 2017.

24. Food and Drug Administration. 2013. Nutri- tion Labeling; Questions L1 through L153. Food Labeling and Nutrition. Available at www.fda. gov/Food/GuidanceRegulation/

GuidanceDocumentsRegulatoryInforma- tion/LabelingNutrition/ucm064904. htm#exempt. Accessed February 2017.

25. Food and Drug Administration. 2016. How to Understand and Use the Nutrition Facts Label. Available at www.fda.gov/Food/ IngredientsPackagingLabeling/Labeling Nutrition/ucm274593.htm. Accessed February 2017.

26. Kurtzweil, P. 1998. Staking a Claim to Good Health. FDA Consumer.

27. Food and Drug Administration. 2015 Guid- ance for Industry: A Food Labeling Guide (8. Claims). Available at http://www.fda. gov/Food/GuidanceRegulation/Guidance DocumentsRegulatoryInformation /LabelingNutrition/ucm064908.htm. Accessed February 2017.

28. Food and Drug Administration. 2016. Structure/Function Claims. Available at www.fda.gov/Food/IngredientsPackaging Labeling/LabelingNutrition/ucm2006881. htm. Accessed February 2017.

29. Academy of Nutrition and Dietetics. 2013. Position of the Academy of Nutrition and Dietetics: Functional Foods. Journal of the Academy of Nutrition and Dietetics 113:1096–1103.

30. USDA Choose My Plate. 2016. Grains. Available at https://www.choosemyplate .gov/grains. Accessed February 2017.

31. Just, D. R., and B. Wansink. 2013. One Man’s Tall Is Another Man’s Small: How the Framing of Portion Size Influences Food Choice. Health Economics. DOI:10.1002/ hec.2949.

32. Herman, C., J. Polivy, et al. 2016. Are Large Portions Responsible for the Obesity Epidemic? Physiology and Behavior 156: 177–181.

33. Downs, J. S., J. Wisdom, et al. 2013. Supple- menting Menu Labeling with Calorie Recommendations to Test for Facilitation Effects. American Journal of Public Health 103(9):1604–1609.

34. Syrad, H., C. Llewellyn, et al. 2016. Meal Size Is a Critical Driver of Weight Gain in Early Childhood. Scientific Reports. DOI: 10.1038/ srep28368.

35. Urban, L. E., A. H. Lichtenstein, et al. 2013. The Energy Content of Restaurant Foods without Stated Calorie Information. Journal of the American Medical Association Internal Medicine 173(14):1292–1299.

36. Young, L. R., and M. Nestle. 2012. Reduc- ing Portion Sizes to Prevent Obesity. Ameri- can Journal of Preventive Medicine 43(5): 565–568.

37. Almiron-Roig, E., I. Solis-Trapala, et al. 2013. Estimating Food Portions. Influence of Unit Number, Meal Type and Energy Density. Appetite 71:95–103.

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