QAs
Mr.Q
chapt01_lecture.pptThe Basics of Nutrition
Chapter 1
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Quiz Yourself True or False
There are four classes of nutrients: proteins, lipids, sugars, and vitamins. T F
Proteins are the most essential class of nutrients. T F
All nutrients must be supplied by the diet, because they cannot be made by the body.
T F
Vitamins are a source of energy. T F
Milk, carrots, and bananas are examples of “perfect foods” that contain all nutrients. T F
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How Did You Do?
False There are six classes of nutrients: carbohydrates, lipids, proteins, vitamins, minerals, and water.
False Proteins are not the most essential class of nutrients.
False All nutrients do not need to be supplied by the diet, because some can be made by the body.
False Vitamins are not a source of energy.
False Milk, carrots, and bananas are not “perfect foods.” No naturally-occurring food supplies all nutrients.
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What Influences Your Eating Habits?
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Why Should You Care
About Your Diet?
Poor diet is associated with 4 of 10 leading causes of death including:
-Heart disease
-Some types of cancer
-Stroke
-Type 2 diabetes
Adequate diet plus regular exercise may reduce your chances of developing these serious chronic diseases.
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Nutrition: The Basics
Key Terms
Diet
Usual pattern of food choices
Nutrients
Life-sustaining substances in food
Nutrition
Scientific study of nutrients and how the body uses them
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Nutrition: The Basics
Key Terms (cont.)
Chemistry
Study of the composition and characteristics of matter and the changes that can occur to it
Cell
Smallest functioning unit in a living organism
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Nutrition: The Basics
Key Terms (cont.)
Metabolism
Chemical processes that take place in living cells
Essential nutrient
Nutrient that must be supplied by food
Deficiency disease
State of health that occurs when a nutrient is missing from the diet
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Six Classes of Nutrients
Carbohydrates
Lipids (includes fat)
Proteins
Vitamins
Minerals
Water
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Note approximate percentages of nutrients in young male and female bodies.
Vitamins are not included, because they are in very small amounts.
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Major Functions of Nutrients
in the Body
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What Is an Essential Nutrient?
An essential nutrient:
- must be supplied by food
- is not synthesized by the body or made in amounts that meet the body’s needs
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Three Key Features of
Essential Nutrients
If missing from diet, a deficiency disease results.
Adding missing nutrient back to diet corrects signs and symptoms of the deficiency.
Scientists can explain why lack of the nutrient caused abnormalities.
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What Are Phytochemicals?
Substances found in plant foods that are not classified as “nutrients” but are beneficial to health.
Plants make hundreds of phytochemicals.
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Phytochemicals of Scientific Interest
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What Lifestyle?
Lifestyle is a person’s way of living such as dietary practices, physical activity habits, and use of drugs.
Lifestyle choices may increase or reduce chances of developing a disease or delay its occurrence for years.
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Lifestyle Choices
High fat diet + inactivity
Risk Factor
Obesity (excess body fat)
Possible Diseases
Heart disease, certain cancers,
type 2 diabetes, and hypertension
Early Death
Changes in Beverage Consumption
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Metrics for Nutrition
Units of scientific measurement often used in nutrition
Length measured in meters
Weight measured in grams
Volume measured in liters
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Common Metric
Prefixes in Nutrition
Metric Basics
1 inch = 2.5 cm
1 ounce = 28 g
1 pound = 454 g
2.2 pounds = 1 kg
Do the Math
If you are 5’5” (65”) (65 x 2.5 = 162.5 cm)
If you weigh 130 lbs
(130 ÷ 2.2 = approx. 59 kg)
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What’s a Calorie?
Kilocalorie or Calorie — measure of food energy
A kilocalorie is the heat energy needed to raise the temperature of 1000 g of water 1o Celsius.
1 kilocalorie = 1 Calorie = 1000 calories
(Kilocalorie is abbreviated as “kcal”)
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Primary Energy Sources
for the Body
Macronutrients and Micronutrients
Macronutrients
-Needed in relatively large amounts
-Provide energy
Carbohydrates, proteins, and fats
Micronutrients
-Needed in very small amounts
-Do not provide energy
Vitamins and minerals
Water: Required in large amounts but not a “macronutrient,” because it does not provide energy (calories)
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Concept 1: Most Naturally Occurring Foods are Mixtures of Nutrients.
A 6-oz potato contains:
4 g protein, 36 g carbohydrate
<1 g fat, plus water, vitamins, and minerals
8 fluid oz fat-free milk contains:
8 g protein, 12 g carbohydrate,
1 g fat, plus water, vitamins, and minerals
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Factors that Contribute to Undernutrition
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Undernutrition During Life Cycle Stages
- Pregnancy
- Infancy
- Preschool years
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Undernutrition in the
United States
Contributing factors:
- Anorexia nervosa
- Alcoholism
- Low income
Food insecurity:
- Defined as a concern about running out of food or not having enough money to buy more food.
- Reported in 11% of U.S. households in 2007
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Major Federally Subsidized Food Programs in the U.S.
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World Food Crisis:
Finding Solutions
The Promise of
Biotechnology
Modifying living things (especially plants and animals) to make improved products
Genetic Modification
Techniques that alter an organism’s DNA
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