Nutrition Basics

1. Nutrition Basics Chapter 9

2. Nutritional Requirements: Components of A Healthy Diet 45 essential nutrients Proteins, fats, carbohydrates, vitamins, minerals, and water Macronutrients Micronutrients Energy in food is expressed as kilocalories 1 kilocalorie = amount of heat it takes to raise the temperature of 1 liter of fluid 1°C 2000 kilocalories (or calories) per day meets a person’s energy needs Kilocalories are commonly referred to as calories, which are much smaller energy units: 1000 calories = 1 kilocalorie Three essential nutrients provide energy: Fat = 9 calories per gram Protein = 4 calories per gram Carbohydrates = 4 calories per gram

3. Figure 9.1 The digestive system

4. Proteins–The Basis of Body Structure Form muscle and bone Form parts of blood, enzymes, some hormones, and cell membranes Building blocks of protein are amino acids Nine essential amino acids Eleven nonessential amino acids Complete proteins provide all essential amino acids in adequate amounts Incomplete proteins usually low in one or two essential amino acids Complementary incomplete proteins can combine to make up missing amino acids Recommended protein intake 0.8 gram per kilogram of body weight (0.36 gram per lb.) 10-35% of total daily calorie intake Average American daily intake is 15-16% of total calories

5. Fats–Essential in Small Amounts Most concentrated source of energy Fats (lipids) can be stored as usable energy Provides insulation and support for body organs Help body absorb fat-soluble vitamins Two types of fats Linoleic acid Alpha-linolenic acid Types and sources of fats Triglycerides - glycerol molecule with 3 fatty acids Animal fats are primarily made of triglycerides Unsaturated Monounsaturated Polyunsaturated Saturated Hydrogenation Trans fatty acids

6. Fats and Health Cholesterol High-density lipoprotein (HDL) = good cholesterol Low-density lipoprotein (LDL) = bad cholesterol Saturated and trans fats pose many health hazards, including heart disease and certain types of cancers Other fats, including monounsaturated fats and omega-3 fatty acids, can be beneficial to health Recommended fat intake Adult men need 17 grams per day of linoleic acid and 1.6 grams of alpha-linolenic acid Adult women need 12 grams per day of linoleic acid and 1.1 grams of alpha-linolenic acid AMDR for total daily fat is 20-35% of daily calories

7. Figure 9.1 Types of fatty acids and their possible effects on health

8. Carbohydrates—An Ideal Source of Energy Supplies energy for body cells Two groups Simple carbohydrates Fruit, sugar, honey, malt, and milk Complex carbohydrates – Starches and most dietary fiber Grains – wheat, rye, rice, oats, barley, and millet Legumes – dry beans, peas, and lentils Tubers – potatoes and yams Digestion Mouth and small intestines Break down into glucose

9. Refined Carbohydrates Versus Whole Grains All grains are whole grains before processing and include: Inner layer (germ) Middle layer (endosperm) Outer layer (bran) During processing, the germ and bran are often removed leaving just the starchy endosperm Refined – less nutritious

10. Glycemic Index Insulin and glucose levels rise and fall following any meal containing carbohydrates Quick rise in glucose and insulin levels = high glycemic index Many different factors influence glycemic index Unrefined grains, fruits, vegetables and legumes have a relatively low glycemic index

11. Recommended Carbohydrate Intake 130 grams needed to meet the body’s requirements for essential carbohydrates Average American eats 200-300 grams daily Carbohydrates should make up 45-65% of total daily calories in an adult’s diet Focus on consuming a variety of foods rich in complex carbohydrates, especially whole grains Health agencies recommend decreased intake of added sugars

12. Fiber – A Closer Look Types of fiber Dietary fiber: Nondigestible carbohydrates (and lignin) that are naturally present in some plants Functional fiber: Nondigestible carbohydrate that has been isolated or synthesized in a lab and added to food as dietary supplement Total fiber: the sum of both Soluble and insoluble fiber Sources of fiber All plant substances Recommended fiber intake 38 grams for adult men 25 grams for adult women Needs to come from foods, not supplements

13. Vitamins—Organic Micronutrients Vitamins: organic (carbon-containing) substances required in small amounts to regulate various processes within living cells Humans need 13 vitamins 4 fat soluble vitamins: A, D, E, and K 9 water soluble vitamins: C and the B-complex vitamins Functions of vitamins Sources of vitamins Human body does not manufacture most vitamins Abundant in fruits, vegetables, and grains Vitamin deficiencies

14. Minerals—Inorganic Micronutrients Minerals: inorganic (non-carbon-containing) compounds that help regulate body functions, aid in growth, maintain body tissues, and help release energy 17 essential minerals Major minerals – need 100 milligrams or more Calcium, phosphorus, magnesium, sodium, sulfur, sodium, potassium, and chloride Trace minerals – need in minute amounts Copper, fluoride, iodide, iron, selenium, and zinc

15. Water—Vital but Often Ignored You are composed of about 50-60% water Can live up to 50 days without food, but only a few days without water Foods and fluids consumed make up 80-90% of your daily water intake Food and Nutrition Board daily requirements Men – 3.7 total liters of water, with 3.0 liters (13 cups) coming from beverages Women – 2.7 total liters of water, with 2.2 (9 cups) coming from beverages

16. Other Substances in Food Antioxidants Protect against damage by free radicals Vitamins C & E, selenium, carotenoids Phytochemicals Substances that may help prevent chronic disease Soy foods Sulforaphane (found in cruciferous vegetables such as broccoli) Allyl sulfides (found in garlic and onions)

17. Dietary Reference Intakes (DRIs) Standards set by Food and Nutrition Board Dietary Reference Intakes (DRIs) Recommended Dietary Allowances (RDAs) Adequate Intake (AI) Tolerable Upper Intake Level (UL) Standards aim to prevent nutrient deficiencies, promote health, and prevent chronic diseases Daily Values are used on food labels and reflect daily guidelines for a 2,000-calorie diet

18. Dietary Guidelines for Americans The 2010 Dietary Guidelines include the following: Reduce overweight and obesity by reducing calorie intake and increasing physical activity Shift food intake patterns to a more plant-based diet rich in vegetables, cooked dry beans and peas, fruits, whole grains, nuts and seeds Increase intake of seafood and fat-free and low-fat milk and milk products Consume only moderate amounts of lean meat, poultry, and eggs Reduce intake of solid fats and added sugars (SoFAS), sodium, and refined grains Meet the 2008 Physical Activity Guidelines for Americans

19. Dietary Guidelines for Americans Energy Balance and Weight Management The obesity epidemic is fueled by the consumption of too many calories from nutrient-poor foods and beverages, combined with lack of physical activity Nutrient Adequacy Energy-dense foods should be replaced with nutrient-dense foods

20. Food Groups to Encourage Dietary Guidelines for Americans recommends eating more Fruits and vegetables High-fiber whole grains Low-fat and fat-free dairy products Seafood Useful dietary patterns: DASH-style pattern, Mediterranean-style patterns, USDA Food Patterns

21. Fatty Acids and Cholesterol Limit intake of saturated fatty acids to less than 7% of total calories Limit cholesterol to less than 300 milligrams per day (200 mg for people at high risk for CVD or diabetes) Limit trans fatty acids from natural sources to less than 0.5% of calories Avoid any trans-fatty acids from hydrogenation Eat two servings of seafood per week for omega-3 Fatty acids (favored fish include salmon, mackerel, and trout)

22. Carbohydrates Sedentary people should decrease consumption of energy-dense carbohydrates to maintain weight Choose foods whole grains and health carbohydrates Avoid added sugars and grain-based desserts

23. USDA’s MyPyramid Key Messages Personalization Daily physical activity Moderation Proportionality Variety Gradual improvement

24. Serving Sizes Grains- 1 slice of bread; 1 small muffin (2.5i-inch diameter); 1 cup ready-to-eat cereal flakes; ½ cup cooked cereal, rice, grains, or pasta; 1 6-inch tortilla Vegetable– 1 cup raw leafy salad greens; 1/2 cup cooked or raw vegetables; 1/2 cup of vegetable juice Fruit – ½ cup fresh, canned, or frozen fruit; 1/2 cup 100% fruit juice; 1 small whole fruit; 1/4 cup dried fruit

25. Serving Sizes Milk -1 cup milk or yogurt; 1/2 cup ricotta cheese; 1.5 oz. natural cheese; 2 oz. processed cheese Meat and Beans – 1 ounce cooked lean meat; 1/4 cup cooked dry beans (legumes) or tofu; 1 egg; 1 tablespoon peanut butter; 1/2 ounce nuts or seeds Oils – 1 teaspoon vegetable oil or soft margarine; 1 tablespoon salad dressing or light mayonnaise Discretionary calories, solid fats, and added sugars

26. The Vegetarian Alternative Types of vegetarian diets Vegans Lacto-vegetarians Lacto-ovo-vegetarians Partial vegetarians Semivegetarians Pescovegetarians A food plan for vegetarians Vitamin B-12 Vitamin D Calcium

27. Dietary Challenges for Special Population Groups Children and teenagers College students Older adults Athletes People with special health concerns

28. A Personal Plan: Making Informed Choices About Food Reading food labels Reading supplement labels

30. Protecting Yourself Against Foodborne Illness Causes of foodborne illnesses Campylobacter jejuni Salmonella Shigella Escherichia coli Listeria monocytogenes Staphylococcus Clostridium botulinum Norovirus Spongiform encephalopathy (“mad cow disease”)

31. Organic foods Must meet limits on pesticide residues and other environmental contaminants Must meet strict USDA guidelines Additives in food Food irradiation Genetically modified foods Food allergies and food intolerances A Personal Plan: Making Informed Choices About Food

32. Nutrition Basics Chapter 9