Proteins

1. Proteins Chapter 5

2. Learning Objectives • Describe the structure and functions of protein • Explain how the body uses protein • Discuss the quality and quantity of protein necessary in the diet • Give examples of complementary proteins

3. Learning Objectives • Describe the unique nutritional benefits of legumes • Distinguish between animal and plant proteins • Plan diets with proteins coming from animal and vegetable sources • Identify appropriate portions of protein foods per serving and for daily consumption

4. 3 oz meat = 21-28 1 oz meat = 7-8 1 cup milk = 8 1 cup yogurt = 8 2 T. peanut butter = 7 1 egg white = 7 ½ c nuts/seeds = 7 ½ legumes/beans = 7 ½ cup grain = 3 1 slice bread = 3 ½ cup veg = 2 1 cup soy milk = 8 1 oz. tofu = 8 ½ cup meat substitute = 7 Veggie Burger = 14 Scoop of protein powder = 14-25 Protein Bars- 7-14 MyPlate- 76 grams Food Protein Sources (grams)

6. Protein Sources are also sources of….. • Iron • B-vitamins (thiamin, niacin, riboflavin, B-6, B-12) • Zinc • Magnesium and vitamin E (nuts/seeds) • Fiber (legumes) • Omega 3 fats (fish, eggs)

7. How the Body Uses Protein • Muscles, organs, blood, bones, nails, hair and skin are mostly protein • Proteins in the blood help transport nutrients and oxygen • Antibodies, enzymes and hormones are composed of proteins

8. How the Body Uses Protein • Necessary for blood clotting • Necessary to maintain acid-base balance within cells

9. How the Body Uses Protein • Energy • 1 gram of protein = 4 calories • Used as fuel after carbohydrate and fat

10. How the Body Uses Protein • Body breaks down protein in muscle tissue if: • Calories very low • Prolonged physical activity • High fever • Severe burns • Some diseases

11. Protein Structure • Amino acids (20) are the building blocks of protein that contain nitrogen in the chemical structure • Essential amino acids (8 or 9) • Cannot be produced by the body • Must be provided by food • Nonessential amino acids • Can be made by the body from essential amino acids

12. Amino Acids

13. Protein • Made of amino acids combined in a specific sequence • Large, complex chemical structures

14. Protein Digestion • Proteins from food are broken down into separate amino acids and then absorbed into the body Hemoglobin

15. Protein Digestion • Digestive enzymes break protein down • Proteases • Pepsin • 50,000 different proteins are created in cells from amino acids in the bloodstream Hemoglobin

16. Complete Proteins • Foods that provide all essential amino acids in amounts to support growth and maintenance of body tissues • High biological value • Primarily from animal sources

17. Complete Proteins • Foods: • Meat • Fish • Poultry • Cheese • Eggs (perfect amount and variety of amino acids) • Milk • Isolated soy protein

18. Incomplete Proteins • Foods that lack one or more of the essential amino acids in sufficient quantity to support growth and maintenance of body tissues • Have one or more limiting amino acids • Lower biological value score • From plant sources

19. Incomplete Proteins • Foods: • Grains • Legumes • Nuts • Seeds • Vegetables

20. Complementary Proteins • Combining foods that complement limiting amino acids • The combination of plant protein foods which when eaten together provide all the essential amino acids.

21. Complementary Proteins • Cereal grain and legumes • Hummus and pita bread • Grain and beans • Black beans and bulgur • Tofu and rice • Nuts and grain • Nut butter sandwich • A small amount of complete protein makes an incomplete protein complete • Cheese and pasta • Pork and beans

22. Protein Recommendations • Body weight • Grams per kg of body weight • 170 pounds ÷ 2.2 = 77.2 kg • 77.2 kg x .8 gram/kg = 62 grams protein a day • Adults- .8 grams/kg (RDA) • Infants- 2.2 grams/kg • Teens- 1.8 grams/kg • Older Adult- 1.3 grams/kg • Malnourished, Health Issues- 1.5-3.0 grams/kg • Athletes- 1.2 - 2.0 grams/kg

23. Protein Needs • World Health Organization: 40 grams protein • Dietary Guidelines for Americans: • 10 -35 % of calories from protein • 2000 calories • 50-175 grams/day

24. Protein and Health: Too Much Protein • High protein foods are often high in fat and cholesterol • Few high protein foods are low-fat foods • No extra health benefit • VERY high protein may decrease calcium absorption and increases work of kidney and liver to process

25. Protein and Health: Too Much Protein cont. • Very high protein, very low carbohydrate diets are difficult to maintain and are not usually nutritionally adequate • High-protein foods are usually more expensive

26. Protein and Health: Too Little Protein • Protein Energy Malnutrition (PEM) • Marasmus • Severe protein-calorie malnutrition • Kwashiorkor • Seen in children in underdeveloped countries • Severe protein malnutrition but with enough calories from starchy foods • Probably not a nutritional problem; due to aflatoxins in the grains eaten

27. Protein and Satiety • Protein is more satiating than carbohydrate diet • Protein reduces hunger

28. Protein Equivalents • MyPlate: 1 ounce protein equivalent = 7 to 8 grams protein • 1 ounce meat, poultry, fish • ¼ cup cooked beans • 1 tablespoon peanut butter • ½ ounce nuts or seeds

29. Protein Sources: Meat • Generally, meats compared in 100 gram or 3 ½ ounce servings • Cuts from loin and round are often leanest • Check ground meats • % • 80 vs 90%

30. Protein Sources: Meat • Most sausages, spareribs, short ribs are high in fat • Game meats are often low in fat • Venison • Buffalo

31. Protein Sources: Poultry • Lighter meat is lower in fat • Much fat under the skin • Skin can be removed before or after cooking

32. Protein Sources • Goose and duck is higher in fat that chicken or turkey • Protein not very different in free-range, organic, kosher, without hormone or other methods of raising

33. Protein Sources: Seafood • Most seafood is high in excellent quality protein • Most seafood is either low in fat or high in heart-healthy fat

34. Protein Sources: Eggs • Egg protein is of highest biological value • Egg white is low-fat protein

35. Protein Sources: Eggs • Omega-3 eggs are produced by feeding fishmeal to chickens, usually cost more • Shell color does not influence nutrients

36. Protein Sources: Dairy • 3 cups or equivalent for most adults • Low-fat, non-fat • Yogurt, especially Greek yogurt

37. Protein Sources: Milk Substitutes • Soymilk is usually protein-rich • Nut, hemp, oat and grain milk is usually low in protein • Some milk substitutes are fortified with calcium and vitamin D

38. Protein Sources: Legumes • Soy protein availability is limited in raw product. • tofu or well-cooked allow protein digested • Textured vegetable protein (TVP) and isolated soy protein are good sources for vegans

39. Protein Sources: Nuts and Seeds • Nuts, nut butters, seeds have protein and fiber • Most are high in heart-healthy fats and high in calories • 1 ounce is only a few nuts but a large portion of seeds

40. Protein Sources: Grains • The limiting essential amino acid is generally lysine • Eat with legumes for complementary protein • Kamut and teff are highest in protein

41. Protein in Cooking • Denaturation • Change in chemical structure of protein by heat, whipping or adding salt or acid • Coagulation • Protein strands break and re-bond, releasing water

42. Protein in Cooking • Gluten • Protein in wheat. Gluten is the protein that influences texture and structure of dough • Amino acids are sometimes used as ingredients • To boost nutrients • As flavor enhancers • Made into sweeteners

43. Vegetarians

44. Vegetarians – Types

45. Meeting the Needs of Vegetarians Key nutrition points • Include a variety of foods including whole grains, legumes, nuts and seeds, fruits and vegetables • Nutrients of concern that may be limited include • Protein • Vitamin B12 • Calcium • Iron

46. The end! Chapter 5