1. Health Benefits of Protein

2. Protein- Positive Image Conjures up images of vitality and strength

3. Protein- Positive Image Has not been accused of being fattening

4. Protein- Positive Image Has not been accused of causing tooth decay or Increasing the risk of heart disease

5. Protein is a "big seller” Protein drinks, pills, and powders fill the shelves of health food stores.

6. Chapter Learning Outcomes 1.Identify the basic structural unit of proteins. 2.Distinguish between essential and nonessential amino acids. 3.Explain the basic steps of protein synthesis and digestion. 4.Discuss conditions that contribute to positive nitrogen balance, negative nitrogen balance, and protein balance.

7. Chapter Learning Outcomes (continued) 6.Identify food sources of protein and foods that provide high and low quality proteins. 7.Plan meals and snacks that reduce animal protein intake. 8.Discuss the pros and cons of vegetarian diets. 9.Describe how protein-energy malnutrition (PEM) can affect the body.

8. Quiz Yourself True or False Quiz Yourself True or False 1.Animal foods such as meat and eggs are almost 100% protein. T F 2.Foods made from processed soybeans can be sources of high quality protein. T F 3.An adult body builder should consume about five times more protein than a healthy adult who is not a body builder. T F 4.Registered dietitians generally recommend that vegetarians take amino acids supplements to increase their protein intake. T F 5.People can nourish their hair by using shampoo that contains protein. T F 

9. How Did You Do? How Did You Do? 1.False Animal foods such as meat and eggs contain some protein, lipids, and lots of water. 2.True Foods made from processed soybeans can be sources of high quality protein. 3.False An adult body builder does not need to consume about five times more protein than a healthy adult who is not a body builder. 4.False Registered dietitians do not generally recommend that vegetarians take amino acids supplements to increase their protein intake. 5.False Hair is composed of protein, not living tissue. Therefore, it cannot be nourished. 

10. What Are Proteins? Complex organic molecules Complex organic molecules – Chemically similar to lipids and carbohydrates Composed of carbon, hydrogen, oxygen, and nitrogen Composed of carbon, hydrogen, oxygen, and nitrogen The human body contains ~100,000 different proteins. The human body contains ~100,000 different proteins.

11. Why We Need Protein Growth and repair of tissues As a secondary source of energy

12. Why We Need Protein Energy source—provides 4 kcal/gram Support & movement—bone matrix, cartilage, muscle (skeletal, heart, peristalsis, etc...) Biochemical reactions—all enzymes are proteins Regulators—some hormones are proteins (insulin) Oxygen carriers—hemoglobin and myoglobin are proteins

13. Why We Need Protein Antibodies are proteins—attack foreign proteins and microorganisms to prevent infections and poisoning Buffering—blood proteins maintain blood pH which keeps the environment favorable for chemical reactions Water balance/osmoregulation—albumin in the Blood Neurotransmitters—nerve signaling

15. Amino Acids Essential Amino Acids 1. Phenylalanine 2. valine 3. threonine 4. Tryptophan 5. isoleucine 6. Methionine 7. histidine 8. lysine 9. leucine Non Essential Amino Acids 1.Glycine 2.Alanine 3.Cysteine 4.Serine 5.Aspartate 6.Asparagine 7.Glutamate 8.Glutamine 9.Proline 10.Tyrosine

16. Protein Sparing When energy intake is adequate, body protein will be spared for protein-specific functions (building tissues, etc…). So carbohydrate and fat spares protein. When energy intake is limiting, even if protein intake is “adequate”, some body protein will be burned for energy.

17. Protein Sparing Protein losses can be minimized during weight reduction by consuming >0.8 g protein/kg each day. However, this does not need to be taken to the extreme such as 2.0 gm protein/kg.

18. Does the Protein Requirement Differ According to the Protein Quality of the Diet? Protein quality is determined by two things: – Digestibility—refers to the amount of the protein that is digested and absorbed – Biologic value—refers to the amino acid make-up of the protein

19. Protein Quality: Digestibility What happens to the nutritional value of a protein if it is not well-digested? Growth and maintenance are slowed because the body manufactures fewer proteins Protein intake= 60 g amino acids 42 g amino acids available for absorption 70% of protein digested (60 x.7

20. Classifying Amino Acids Essential Amino Acids Cannot be made by the body, so must be supplied in the dietCannot be made by the body, so must be supplied in the diet 9 of the 20 amino acids9 of the 20 amino acids Nonessential Amino Acids Nonessential Amino Acids Can be made by the bodyCan be made by the body 11 of the 20 amino acids11 of the 20 amino acids

21. Protein Quality What happens if the pattern of essential amino acids in the diet don’t match the body’s required pattern of essential amino acids? Can your body build what it needs to? NO!

22. Quality of Protein in Foods The highest quality food proteins are those that are both very digestible and have an essential amino acid pattern closely matching the amino acid requirements of the body. The food proteins of highest quality are: – Egg—contains the highest quality protein of all foods – Milk – Meat, fish

23. Limiting Amino Acid The limiting amino acid in a food is the essential amino acid that is present in the smallest amount relative to the essential amino acid requirement of the body.

24. Limiting Amino Acids in Foods FoodMost Limiting AAHigh Levels Grains, nuts, seeds Lysine, threonineMethionine Legumes (includes soy and peanuts) MethionineLysine, threonine CornLysine, tryptophan Methionine Green Leafy Vegetable Methionine

25. Protein and Effect in the Body A diet containing lots of animal protein may cause: – high cholesterol heart disease – more bone mineral loss osteoporosis – Why? Protein or other components? Soy protein substituted for animal protein – lowers blood cholesterol, may prevent – osteoporosis—why? Protein or other components?

26. How Does it Work Addition—Adding more protein, at some point, you’ll have enough of the limiting essential amino acid Supplementation—A better quality protein can fill in the missing essential amino acids Complementation—What one protein lacks the other has

27. Overcoming Protein Quality Shortages How would you improve the protein quality of a diet? – Eat more protein—addition – Eat higher quality protein—supplementation – Combine proteins of lower quality that complement each other—complementation

28. Improving Protein Quality AdditionLarge amounts of rice, bread or pasta are eaten in many countries SupplementationMilk + cereal, meat in vegetable stew, egg in stir-fried vegetables Complementationpeanut butter sandwich, tortillas/beans, rice & tofu, grains and leafy vegetables

29. You need to know the nine essential amino acids A way to remember the essential amino acids "These Ten Valuable Amino-acids Have Long Preserved Life In Man." OR PV. TTM HILL

30. The Essential and Nonessential Amino Acids Insert table 7.1

31. A quick review The building blocks of proteins are referred to as: (a)amino acids (b) enzymes (c )hormones (d)Antibodies A body function that is not associated with protein is (a) blood clotting (b)cholesterol synthesis (c) formation of antibodies (d) tissue growth and maintenance

32. A quick review List the functions of protein Name the three groups of atoms that make up a protein. How many types of amino acids are needed to make human protein? How many of these amino acids are essential?

33. Proteins in Foods Nearly all foods contain some protein, but no natural food is 100% protein. Nearly all foods contain some protein, but no natural food is 100% protein. Animal foods typically have more protein than plant foods. Animal foods typically have more protein than plant foods. – Seeds, tree nuts, and legumes supply more protein than fruit or the edible leaves, roots, flowers, and stems of vegetables.

34. Protein Contents of Some Commonly Eaten Foods Insert Table 7.2 Insert Table 7.2

35. What Are Legumes? Legumes Legumes – Plants that produce pods with a single row of seeds Examples: Soybeans, peas, peanuts, lentils, and beans Soybeans, peas, peanuts, lentils, and beans Insert figure 7.3

36. Protein Quality High-quality protein or “Complete protein” High-quality protein or “Complete protein” – Protein that contains all 9 essential amino acids in amounts that support growth- meat, poultry, egg, milk – Most animal products and products made with processed soy – Note: Well digested and absorbed in the body Low-quality protein Low-quality protein – Protein that lacks or has inadequate amounts of one or more of the essential amino acids – Most plant foods (except processed soy) and gelatin and gelatin Note: Body does not digest as efficiently.

37. What Happens to Protein in Your Body? How Your Body Synthesizes Proteins How Your Body Synthesizes Proteins – Cells assemble the 20 amino acids in specific sequences according to information provided by DNA. – Amino acids are connected by peptide bonds. – Peptides Chains of fewer than 15 amino acids Chains of fewer than 15 amino acids – Polypeptides Proteins made of > 50 amino acids Proteins made of > 50 amino acids

38. What Is a Protein? Each distinctive bead in the illustration represents a different amino Each distinctive bead in the illustration represents a different amino acid. acid. The “hook” that connects the “beads” represents a peptide bond. The “hook” that connects the “beads” represents a peptide bond. Insert figure 7.4

39. Peptide Bond Insert figure 7.5 Insert figure 7.5

40. Protein Synthesis Insert figure 7.6 Insert figure 7.6

41. A Protein Takes Shape Insert figure 7.7 Insert figure 7.7

42. Sickle Cell Anemia If the DNA code is faulty, the wrong amino acid may be inserted into a protein. For example, sickle cell disease that affects red blood cells If the DNA code is faulty, the wrong amino acid may be inserted into a protein. For example, sickle cell disease that affects red blood cells Insert figure 7.4

43. Protein Denaturation Denaturation Altering a protein’s natural shape and function by exposing it to conditions such as heat, alcohol, acid, and physical agitation Altering a protein’s natural shape and function by exposing it to conditions such as heat, alcohol, acid, and physical agitation – Heat denatures the protein in raw eggs. – Acidic lemon juice “curdles” the protein in milk. – Hydrochloric acid denatures food proteins in the stomach, making them easy to digest. – Physical agitation includes whipping protein-rich foods (e.g., beaten egg whites). Once a protein has been denatured, it cannot return to its original shape. Once a protein has been denatured, it cannot return to its original shape.

44. Denaturation Insert Figure 7.9

45. Protein Turnover Protein turnover Protein turnover – Breaking down old or unneeded proteins into amino acids and recycling the amino acids Amino acid “pool” Amino acid “pool” – Amino acids that have not been incorporated into proteins Endogenous amino acids Endogenous amino acids – Those available from the amino acid pool Exogenous proteins Exogenous proteins – Those from dietary sources

46. Transamination and Deamination Transamination – Transfer of nitrogen-containing group from an unneeded amino acid to a carbon skeleton, forming an amino acid Deamination – Removal of nitrogen-containing group from an unneeded amino acid

47. Example of Transamination and Deamination Insert Figure 7.10

48. The Liver and Deamination Ammonia (NH 3 ) is converted to urea that the kidneys excrete in urine. Insert Figure 7.11

49. What happens if you eat too protein? The body DOES NOT store the extra amino acids in muscles or other tissues. The extra amino acids undergoes deamination. The cells convert the carbon skeletons into glucose or fat, or metabloizes them for energy.

50. Nitrogen Balance Nitrogen balance (or equilibrium) Balancing nitrogen intake with nitrogen losses Positive nitrogen balance Body retains nitrogen than it loses Body retains more nitrogen than it loses Negative nitrogen balance Body loses more nitrogen than it retains

51. P ositive Nitrogen Balance Occurs during growth, pregnancy, recovery from illness, and as a result of certain hormones and resistance exercise insert Figure 7.12

52. Nitrogen Equilibrium Occurs when healthy adults meet protein and energy needs Nitrogen Equilibrium Occurs when healthy adults meet protein and energy needs Insert Figure 7.12

53. Negative Nitrogen Balance Occurs with  protein intake, kidney disease, blood loss, bed rest, fever, injuries, burns, or  thyroid hormone or cortisol Insert Figure 7.12

54. How Much Protein Do You Need? Daily protein needs of healthy adults: Daily protein needs of healthy adults: – RDA = 0.8 g/kg body wt Protein needs increase during periods of growth, pregnancy, lactation, and recovery from illness or injury. Protein needs increase during periods of growth, pregnancy, lactation, and recovery from illness or injury.

55. Determining Protein Needs Using the RDA formula of 0.8 g of protein/kg of body wt, what is the RDA for protein for a person weighing 165 lbs? Using the RDA formula of 0.8 g of protein/kg of body wt, what is the RDA for protein for a person weighing 165 lbs? 1)Convert weight in lbs to weight in kg (165  2.2 = 75 kg) 2)Multiply kg of body wt by 0.8 75 X 0.8 = 60 Therefore, a person weighing 165 lbs will meet his/her RDA for protein by consuming 60 g of protein per day

56. Protein Digestion Protein Digestion Protein digestion begins in the stomach. Protein digestion begins in the stomach. – Hydrochloric acid denatures proteins – Pepsin, an enzyme, digests proteins into smaller polypeptides. Polypeptides enter the small intestine Polypeptides enter the small intestine – The enzymes trypsin and chymotrypsin break down polypeptides into shorter peptides and individual amino acids.

57. Protein Absorption Protein Absorption Absorption occurs in the small intestine Absorption occurs in the small intestine – Absorptive cells release enzymes that digest most small peptides into individual amino acids. – Individual amino acids and some di- and tripeptides enter absorptive cells, where they are completely digested to amino acids.

58. After Absorption… After Absorption… Amino acids enter portal vein and travel to the liver Amino acids enter portal vein and travel to the liver – Liver keeps some amino acids for its own use and releases others into general circulation. Most proteins are digested and amino acids absorbed Most proteins are digested and amino acids absorbed – Very little protein is eliminated in feces.

59. What Is A Food Allergy? What Is A Food Allergy? Allergy Allergy – Inflammatory response resulting when body’s immune system reacts inappropriately to a substance that is typically harmless Allergen — the offending substance Allergen — the offending substance – Most food allergens are proteins that escape digestion and are absorbed as whole proteins.

60. Common Signs of Food Allergies Common Signs of Food Allergies Signs occur within a few minutes or couple of hours and typically include: Signs occur within a few minutes or couple of hours and typically include: – Hives (red raised bumps on skin) – Swollen or itchy lips – Skin flushing – Scaly skin rash (eczema) – Difficulty swallowing – Wheezing and difficult breathing – Abdominal pain, vomiting, and diarrhea

61. Common Food Allergens Protein-rich foods -Cow’s milk -Eggs -Peanuts - Wheat - Soybeans - Fish and shellfish Nonproteins - Food dyes - Sulfites added to: Wine Fruits Vegetables Shellfish

62. Who Develops Food Allergies? People with family history of food or environmental allergies People with family history of food or environmental allergies ~ 4% of children 5 to 17 yrs ~ 4% of children 5 to 17 yrs Most outgrow by age 5 yrs Most outgrow by age 5 yrs – Allergies to nuts, seafood, and wheat are typically not outgrown ~ 2% of adults ~ 2% of adults

63. Gluten and Celiac Disease Gluten and Celiac Disease Gliadin Gliadin – Protein found in gluten of wheat, buckwheat, barley, and rye – Triggers inflammatory response in small intestine – Condition called celiac disease Symptoms include Symptoms include – Chronic diarrhea, weight loss, poor growth in children Treatment Treatment – Avoid gluten-containing foods

64. Other Sources of Glutensrces of gluten Medications and vitamin/mineral supplements Glues and pastes Communication wafers Grain derived alcohol such as beer Contamination of safe grains with unsafe grains – Bulk grains at food stores – Toasters – Airborne flour dust Eating out can be tricky – Growing number of Gluten-free Restaurants “Beyond the Grain” in Des Moines

65. Treatment of Food Allergies Treatment of Food Allergies Avoid offending foods Avoid offending foods Read food labels to check for allergens Read food labels to check for allergens Food Allergen Labeling and Consumer Protection Act requires manufacturers to identify allergenic ingredients on product labels. Food Allergen Labeling and Consumer Protection Act requires manufacturers to identify allergenic ingredients on product labels. Educate teachers and other adults of allergic children’s need to avoid certain foods Educate teachers and other adults of allergic children’s need to avoid certain foods

66. Treating Severe Allergic Reactions Emergency treatment for anaphylaxis (a severe allergic reaction) may involve injecting a special medication. Insert photo of girl using epi Pen from page 200

67. What Is PKU? Phenylketonuria (PKU) Phenylketonuria (PKU) – Genetic disorder – Affects ~ 1/15,000 infants – Caused by lack of enzyme that converts the amino acid phenylalanine to another compound – If undiagnosed, infant will develop mental retardation by first birthday. Insert photo of phenyl warning from page 201

68. Low Phenylalanine Diet Infancy Phenylalanine-free formula and low-phenylalanine foods Childhood and adult years Allowed: fruits, vegetables, and special low- phenylalanine foods Avoided: nuts, milk and milk products, eggs, meats, and foods and beverages containing aspartame (e.g., Nutrasweet or Equal)

69. Questions Share some of the things you understand about protein.

70. Question What information is fuzzy at this time?

71. Protein Consumption Patterns Insert Figure 7.14

72. MyPyramid Plan: Recommendations for Protein Intake Choose lean or low-fat meat and poultry Choose lean or low-fat meat and poultry – Lean cuts of beef include: Round steaks, top round, loin, top sirloin, chuck and arm roasts Round steaks, top round, loin, top sirloin, chuck and arm roasts – Lean pork cuts include: Loin, tenderloin, and center loin Loin, tenderloin, and center loin Choose “extra lean” ground beef Choose “extra lean” ground beef – At least 90% lean Trim visible fat from meats Trim visible fat from meats

73. Understanding Nutritional Labeling Nutrition Facts panel only provides grams of protein Nutrition Facts panel only provides grams of protein Panel does not provide information concerning protein quality Panel does not provide information concerning protein quality – Judge protein quality by reviewing items in the ingredient list Figure 7.15

74. Eating Well for Less - Substitute eggs, milk, cheese, and yogurt for meat, fish, or poultry. - Make meals that contain less animal proteins and more plant proteins. - Extend cereal proteins with eggs and milk (e.g., pancakes, waffles, crepes, or cereal with milk). - Include more legumes in meals (e.g., chili, bean soups, and stews) while reducing meat content.

75. Combining Complementary Proteins Complementary combinations - Mixing certain plant foods to provide all essential amino acids without adding animal proteins Amino acids often low or limiting in plant proteins: tryptophan, threonine, lysine, and methionine

76. Limiting Amino Acids in Foods FoodMost limiting AA High Levels Grains,nuts, seedsLysine, ThreonineMethionine Legumes (includes soybean and peanuts) MethionineLysine, Threonine PeanutsLysine, Threonine, Methionine CornLysine, TryptophanMethionine Green leafy vegetablesMethionine

77. Complementary Dishes Insert photo of girl making BPJ from page 207 Insert couscous photo from page 209 Peanut Butter (legume) on Bread (grain) Couscous (grain) with Chickpeas (legume)

78. Complementary Protein Dishes Insert Table 7.3 Insert Table 7.3

79. Vegetarianism Vegetarians - People who eat plant-based diets Types of Vegetarians Lactovegetarian Lactovegetarian Consumes milk and milk productsConsumes milk and milk products Ovovegetarian Ovovegetarian Consumes eggsConsumes eggs Lactoovovegetarian Lactoovovegetarian Consumes eggs and milk and milk productsConsumes eggs and milk and milk products Vegan Vegan Consumes only plant foodsConsumes only plant foods

80. Is Vegetarianism a Healthy Lifestyle? Pros Compared to nonvegetarians, vegetarians tend to: – Weigh less – Have less heart disease (eat less saturated fat and cholesterol) – Often exercise more, meditate for relaxation, and avoid tobacco and alcohol Cons If diets are poorly planned, vegetarians may lack: – Kilocalories – High-quality protein – Omega-3 fatty acids – Vitamins B-12 and D – Zinc, iron, and calcium

81. Vegetarian Children and Teens Children May be difficult to consume adequate protein and energy, because plant foods tend to be filling – Growth rates of vegan children need close monitoring. Teens Pro: Can be healthy diet because more fruits and vegetables are consumed Con: May be at risk of anorexia nervosa, an eating disorder

82. Vegetarian Women Pregnancy May need vitamin B-12 supplements – Infant could be deficient in B-12 Breastfeeding Breastmilk may be deficient in vitamin B-12 – Infant may develop severe developmental delays if fed breast milk that lacks vitamin B-12

83. Meatless Menu Planning Ideas Insert Table 7.4 Insert Table 7.4

84. Protein Adequacy Excessive Protein Intake – May  risk of heart disease and cancers of the colon/rectum, prostate, pancreas, and breast What about High-Protein Weight-Loss Diets? – Diets decrease feelings of hunger and increase sense of fullness. – More info about safety of high-protein weight loss diets in Chapter 10

85. Protein Deficiency Uncommon in the U.S. – May occur in: elderly or low-income people elderly or low-income people persons with alcoholism, anorexia nervosa, or intestinal tract disorders persons with alcoholism, anorexia nervosa, or intestinal tract disorders

86. Kwashiorkor and Marasmus Protein-energy malnutrition (PEM) – Results from chronic lack of food or poor food choices Two types of PEM: – Kwahsiorkor Adequate energy intake but intake of high-quality protein is low Adequate energy intake but intake of high-quality protein is low » Edema – Marasmus Starvation—extreme weight loss Starvation—extreme weight loss

87. Marasmic Kwashiorkor Characterized by edema in the abdomen, lower legs, and feet Insert figure 7.17

88. Severe Protein- Energy Malnutrition Insert figure 7.18

89. Chapter 7 Highlight Building a Bulkier Body How to increase muscle mass? Resistance training is the only safe and reliable way.Resistance training is the only safe and reliable way. Dietitians generally do not recommend eating large amounts of protein-rich foods.Dietitians generally do not recommend eating large amounts of protein-rich foods.

90. How Resistance Training Builds Bigger Muscles During training, muscle proteins break down. – Synthesis occurs during recovery and lasts ~ 24 to 48 hrs. positive nitrogen balanceMuscles grow larger if adequate energy and protein are available (positive nitrogen balance).

91. Proteins: General Advice for Athletes Since carbohydrates spare proteins, eat a snack before or after exercise that includes adequate carbohydrate and protein. notProtein supplements are not needed for healthy persons. – If supplements are used, avoid those that contain a single amino acid. Avoid high-protein diets, especially ones high in red meats.

92. Be able to: List the primary functions of proteins in the body Short Time Plain Cook = CHEF Structural, Transport, Pigment, Contractile C-ontractile H-ormones E-nzymes F-luid balance