NUTRITION

1. NUTRITION

2. INTRODUCTION • For most people in the United States good nutrition is a matter of informed choice

3. Poor nutritional habits can contribute to ill health • Too much cholesterol • Too much saturated fat • Too much refined sugar • Too much salt • Too few complex carbohydrates • Taking in more calories than expended

4. Good nutrition can be achieved by wise diet planning • Food fads are unnecessary • Diets should contain enough essential nutrients • Proper calories should be consumed • A variety of foods is recommended

5. DIETARY GUIDELINES FOR EATING RIGHT • To encourage and promote healthy dietary choices, the U.S. government, the World Health Organization, and the American Heart Association and American Cancer Society promote guidelines for good nutrition

7. Dietary Guidelines • Aim for Fitness • Aim for a healthy weight • Be physically active each day

8. Dietary Guidelines • Build a Healthy Base • Let the Pyramid guide your food • choicesChoose a variety of grains • daily, especially whole grains • Choose a variety of fruits and vegetables daily • Keep food safe to eat

9. The Food Guide Pyramid • To help implement the dietary guidelines, the U.S. government created the “Food Guide Pyramid” which promotes diets emphasizing grains, fruits, and vegetables, with moderate to little consumption of meat and diary products, and very little sweets and fats

10. Dietary Guidelines • Choose Sensibly • Choose a diet that is low in saturated fat and cholesterol and moderate in total fat • Choose beverages and foods to moderate your intake of sugarsChoose and prepare foods with less saltIf you drink alcoholic beverages, do so in moderation

11. American Heart Association’s Dietary Guidelines (with your heart in mind) • Total fat intake should be less than 30 percent of total calories • Saturated fatty acid intake should be less than 10 percent of total calories • Polyunsaturated fatty acid intake should be no more than 10 percent of calories

12. Monounsaturated fatty acids make up the rest of the total fat intake, about 10 to 15 percent of total calories • Cholesterol intake should be no more than 300 milligrams per day • Sodium intake should be no more than 300 milligrams (3 grams) per day

13. American Cancer Society’s Dietary Guidelines (for reducing cancer risk) • Maintain desirable body weight • Eat a varied diet • Include a variety of both vegetables and fruits in the daily diet • Eat more high-fiber foods, e.g., whole grain cereals, legumes, vegetables, fruits • Cut down on total fat intake • Limit consumption of alcoholic beverages, if you drink at all • Limit consumption of salt-cured, smoked, and nitrate-preserved foods

14. Even though both guidelines appear to be different, the ultimate goal of a good nutritious diet can be achieved by following either one • In 1988 the first Surgeon General’s Report on Nutrition and Health offered comprehensive documentation for recommended dietary changes

16. There are those who criticize the Food Guide Pyramid because they say it accommodates politically powerful meat and dairy industries • Proponents of the Guide say that it provides a pictorial display placing the most healthy foods at the broad base and the least healthy at the top; they believe this allows for people to stop counting calories and build diets based on foods at the bottom of the Pyramid

17. A pattern for daily healthy food choices include • Choosing daily from breads, cereals, and other grain products, fruits, vegetables, meat, poultry, fish, and milk, cheese, and yogurt • Including different foods from within the groups • Having the smaller number of servings suggested from each group • Limiting total amount of food eaten to that needed to maintain desirable body weight • Choosing foods that are low in fat and sugars • Managing your intake of fats, sweets, and alcoholic beverages

18. READING THE “NEW” FOOD LABEL • In 1990, the Nutritional Labeling and Education Act (NELA) became law • The Food and Drug Administration oversees this law which includes educating the consumer FDA Labeling

19. Four primary messages officials hope you will gain when you read the new food label • You can believe the claims on the package • You can more easily compare products because serving sizes will be more comparable for similar products • By using the percent daily value, you can quickly determine whether a product is high or low in a nutrient • By consulting the daily values, you can determine how much, or how little, of the major nutrients you should eat daily

20. RDA lists values for protein, eleven vitamins, seven minerals • Assumes if these nutrients are present in the recommended amounts, then all others will be, too • Assumes the diet contains animal protein to provide essential amino acids • Assumes individuals are healthy and not stressed • Makes separate recommendations for pregnant and lactating women, and children

21. Recommended [Daily] Dietary Allowances (RDAs) outline the nutrient requirements of most Americans • Set by the Food and Nutrition Board of the National Academy of Sciences • Updated periodically to take into account recent research

22. Energy for Life • Food is the source of energy for life • Ultimate source of food energy is sunlight • Plants convert solar energy into plant material • Humans get energy by eating plants or animals that have eaten plants

23. Energy is measured in calories • One calorie is the energy required to raise one gram of water from 14.5 degrees to 15.5 degrees Celsius • Nutritional calorie is a unit of energy often referred to as a kilocalorie • A kilocalorie is equivalent to 1,000 calories

24. Different foods provide different amounts of energy Carbohydrates4 calories per gram Protein4 calories per gram Fat/Lipid9 calories per gram Amount of energy needed for physical activity depends on strenuousness of activity, body weight, and environmental temperature Energy needs are being met if a person is neither overweight nor underweight

25. THE COMPOSITION OF FOOD • Foods contain six types of chemical substances • Proteins • Carbohydrates • Lipids (fats) • Vitamins • Minerals • Water

26. Digestion is the breakdown of food and the absorption of nutrients by the gastrointestinal system • The mouth is the initial site of digestion • Chewed and softened food is passed from the mouth to stomach via the esophagus for additional breakdown • Nutrients are absorbed from the intestines into the blood • The liver regulates the release of nutrients • Nondigested material is excreted in feces

27. Proteins are involved in virtually all essential functions of the body • Primary components of the skeleton • Make up hair and nails • Thousands of chemical reactions mediated by enzymes • Antibodies protect body from foreign substances and microorganisms • Hemoglobin transports oxygen via circulatory system • Proteins act as receptors on surfaces of cells

28. Proteins are made up of amino acids linked together in chains • Twenty different amino acids • Each type of protein has a unique amino acid composition and sequence • Optimum protein synthesis requires all amino acids in sufficient amounts

29. Amino acids are classified as essential and nonessential • Eight essential amino acids are required by adults and nine are requiredby infants • Animal sources of protein include: milk, milk products, meat, fish, poultry and eggs • Plant sources of protein include: breads and cereals, legumes, nuts and seeds

30. Humans must obtain the eight essential amino acids from food • Daily supply required; amino acids are not stored • High-quality dietary protein matches the body’s needs for essential amino acids • Most vegetable protein has insufficient essential amino acids; must mix protein from different sources to make complete protein • Generally supplied by daily intake of 45-60 grams of dietary protein

31. High meat consumption may contribute to disease • Most people in the U.S. and Canada consume twice the protein they actually utilize • Many kinds of meat are high in fat

32. Countries with high meat consumption (New Zealand, U.S. and Canada) have high incidences of colon cancer • May be due to pollutants in the meat (cancer-causing/cancer-promoting pesticide residues (DDT), industrial chemicals (PCBs), hormone growth promoters (DES), dyes for color enhancement, and preservatives such as nitrates and nitrites) • May also be due to the way meat is digested

33. THE COMPOSITION OF FOOD:Carbohydrates • Nearly all the body’s cells use energy stored in carbohydrate molecules and are the principal source of the body’s energy • Carbohydrates are also used to manufacture DNA (deoxyribonucleic acid)

34. The body can manufacture carbohydrates from other nutrients • Because of this they are not considered essential nutrients • Carbohydrates are needed in diets to prevent breakdown of body protein (as in muscle tissue)

35. Simple sugars - a class of carbohydrates called monosaccharides; all carbohydrates must be reduced to simple sugars to be digested Complex carbohydrates - a class of carbohydrates called polysaccharides; foods composed of starch and cellulose There are two kinds of carbohydrates:

36. THE COMPOSITION OF FOOD:Carbohydrates: Simple Sugars • Simple sugars are made of one or two molecules only • Glucose is the most common simple sugar and is found in all plants and animals • Glucose circulates in the bloodstream and is commonly referred to as “blood sugar” • Principal cellular energy source • Body converts all sugars to glucose • Used as sweet additive in manufactured foods (“corn sugar”)

37. THE COMPOSITION OF FOOD:Simple Sugars: Fructose • Fructose is one of the sweetest sugars found in fruits and honey • Chemically similar to glucose • Sweeter than glucose and other simple sugars which means you need less to taste sweet

38. THE COMPOSITION OF FOOD:Simple Sugars: Sucrose • Sucrose is common table sugar (also the “refined” sugar added to many packaged foods) • Consists of one glucose and one fructose molecule • Glucose and fructose are split during digestion

39. THE COMPOSITION OF FOOD:Simple Sugars: Lactose • Lactose is found principally in diary products • Consists of one glucose molecule plus one galactose molecule • When lactose is digested, glucose and galactose are separated and the galactose is converted to glucose

40. Most babies can digest lactose, however, some older children and adults cannot because they lack the enzyme lactase, which splits lactose into glucose and galactose • Lack of this enzyme causes gastrointestinal upset, diarrhea, and sometimes cause a severe illness in those who are lactase-deficient (or sometimes referred to as lactose intolerant)

41. THE COMPOSITION OF FOOD:Carbohydrates: Complex Carbohydrates • Complex carbohydrates are many simple sugars linked together • Sources include: grains (wheat, rice, corn, oats, barley); legumes (peas, beans); the leaves, stems, and roots of plants; and some animal tissue

42. The are two main classes of complex carbohydrates: starch (which is digestible)and fiber (which is not digestible)

43. THE COMPOSITION OF FOOD:Complex Carbohydrates: Starch • Starch consists of many glucose molecules linked together • Animal and humans produce a starch in muscle and liver tissue called glycogen • Glycogen breaks down when the organism needs glucose to produce energy

44. Starch in the diet comes primarily from wheat • Wheat kernels crushed to liberate bran, endosperm, and germ • 70 percent extraction produces common white flour (mostly endosperm) primarily used in baking • 70 percent extraction flour has lost many nutrients, some of which are replaced by the manufacturer, but not all • 90 percent extraction is whole grain flour • Not all brown bread is “whole grain”

45. THE COMPOSITION OF FOOD:Complex Carbohydrates: Fiber • There are two kinds of fiber, insoluble fiber and soluble fiber • Insoluble fiber cannot dissolve in water • Soluble fiber can be dissolved in water • Insoluble fiber is made up of cellulose and hemicellulose

46. It is recommended that individuals consume 20-35 grams of fiber daily, regardless of the type of fiber (the differences in insoluble and soluble fiber are not significant for nutritional and health purposes) • Fiber adds bulk to feces, preventing constipation and related disorders

47. Fiber decreases the time material spends in the GI tract, helping reduce risk of diverticular disease and cancer of the colon and rectum • High fiber diets may also help reduce the risk of heart disease and some cancers

48. THE COMPOSITION OF FOOD:Lipids (Fats) • Lipids are a group of substances that are relatively insoluble in water • Some of these substances include: • Triglyceride (body fat) • Some of these substances include cholesterol (a fat-like compound occurring in bile, blood, brain and nerve tissue, liver and other parts of the body)

49. Lecithin which is essential to cell membranes • Steroid hormones • Vitamins A, D, E, K • Bile acids

50. Linoleic acid is the only essential dietary lipid; it is found in safflower, sunflower, and corn • A fat is classified as saturated, monounsaturated, or polyunsaturated • Saturated and unsaturated fats are made up of fatty acids (saturation refers to the number of hydrogen atoms in the fatty acids)