Chapter 4

1. Chapter 4 Nutrition and You

2. Learning Objectives • Identify the six classes of nutrients and explain their functions in the body. • Describe how to use Dietary Reference Intakes, food labels, the Dietary Guidelines for Americans, and MyPyramid to design a healthful diet. • Explain how nutrition guidelines can vary depending on a person’s age, gender, activity level, and dietary preferences or needs. • Identify strategies for handling food safely. • Analyze your current diet and create a personalized plan for improving your nutrition.

3. Did You Know? • The average person in the U.S. consumes the equivalent of 30 teaspoons of added sugar each day. • A meal consisting of a McDonald’s Big Mac, extra large fries, and apple pie contains 1,430 calories, 47% of which is fat. • Eight foods cause more than 90% of all food allergies: milk, eggs, peanuts, tree nuts, soy, wheat, fish, and shellfish.

4. WHAT ARE NUTRIENTS?

5. Nutrients • Your body relies on food to provide chemical compounds called nutrients. • During digestion, the food you eat is broken down into nutrients that are small enough to be absorbed into your bloodstream.

6. The Digestive Process

7. Nutrients • Six major classes of nutrients are found in food: • Carbohydrates • Fats (more appropriately called lipids) • Proteins • Vitamins • Minerals • Water

8. Nutrients • Essential nutrients must be obtained from food or supplements because your body either (1) cannot produce them, or (2) cannot make them in sufficient quantities to maintain health.

9. Macronutrients • Nutrients your body needs in relatively large quantities. • Carbohydrates • Fats • Proteins • Water • Carbohydrates, fats, and proteins are known as energy-yielding nutrients. • These provide you with the energy needed to move, think, and survive.

10. Micronutrients • Nutrients your body needs in relatively small quantities. • Vitamins • Minerals

11. Calorie • A kilocalorie (kcal) is a measurement of the amount of energy that food provides. • Specifically, the amount of energy required to raise the temperature of one kilogram of water by one degree Celsius. • Popularly known in the media and on food labels as a calorie. • Energy nutrients differ in calorie content. • Vitamins, minerals, and water provide no energy.

12. Carbohydrates • The body’s universal energy source. • Most body cells use carbohydrates for energy. • There are two categories of carbohydrates. • Simple • Complex • Sugar molecules are the basic building blocks of carbohydrates.

13. Simple Carbohydrates • Constructed from just one or two sugar molecules. • This means they are more easily digested. • These are often just known as sugars, with six important in nutrition: • Glucose, fructose (fruit sugar), galactose, maltose, sucrose (table sugar), lactose (milk sugar)

14. Simple Carbohydrates • Your body is unable to distinguish between natural sugars and added sweeteners. • Chemically, they are the same. • It’s better to choose foods with naturally occurring sugars that provide other nutrients and vitamins.

15. How Much Sugar? • Discussion Questions • What is the triple threat from consuming too much added sugar? • What are three tips for cutting out added sugar in your diet? • What are the health benefits of cutting out extra sugar from your diet?

16. Complex Carbohydrates • These are made up of chains of multiple sugar molecules. • They take longer to digest. • Often called starches, except for • glycogen, a storage form of glucose in animal tissues, and • fiber, a non-digestible component of plants. • Found in a variety of plants (grains, legumes, vegetables, fruits).

17. Whole Grains • Unrefined grains, or whole grains, include three parts: bran, germ, endosperm. • Examples include rolled oats, popcorn, brown rice, whole wheat, rye, and quinoa. • The bran and germ contain vitamins, minerals, fiber, phytochemicals, and antioxidants. • These help maintain body functions and may reduce risk of certain diseases. • Refined grains include only the endosperm, removing fiber and some nutrients. • Examples include white bread, most pasta, white rice, most baked goods.

18. A whole grain includes the bran, endosperm, and germ. Whole wheat bread is an excellent source of whole grain.

19. Recommended Carbohydrate Intake • Aim to consume at least 130 grams of carbohydrates each day. • Include both simple and complex carbohydrates. • If only the minimum is met, it is likely that a diet is inadequate in other nutrients and in fiber. • Adults should consume about half of their total daily calories as carbohydrate. • The actual amount depends on the total calories you require each day.

20. Lipids • Lipids are a group of substances that are not soluble in water. • They help your body absorb fat-soluble vitamins. • They cushion and insulate your organs. • They add flavor and tenderness to foods. • They are the most concentrated energy source in the diet (9 calories per gram). • Lipids supply your body with energy both during activity and during sleep.

21. Fats • Fats are the type of lipid found most abundantly in the diet. • Found in a wide variety of plant and animal foods.

22. Other Lipids in Your Diet • Two other lipids are present in foods. • Sterols (cholesterol): Found in animal-based foods. • Phospholipids: Found in peanuts, egg yolks, and some processed foods. • You don’t need to consume cholesterol or phospholipids in your diet, as both are produced by the body.

23. Dietary Fats • Dietary fats are more precisely known as triglycerides. • These compounds contain the chemical glycerol attached to three fatty acid chains. • Depending on the structure of the chains, one of three fats is formed. • Saturated fats • Unsaturated fats • Trans fats • Most fatty foods contain all three types of fats.

24. Saturated Fats • Fatty acid chains that are saturated with hydrogen. • Solid at room temperature. • Found in animal products, dairy products, and tropical oils. • Can increase the level of low-density lipoprotein (LDL) cholesterol in the blood. • A high level of LDL and/or total blood cholesterol is a major risk factor for heart disease, increases stroke risk, and can lead to a heart attack.

25. Ice cream is loaded with saturated fat.

26. Unsaturated Fats • Fatty acid chains that have one or more areas not saturated with hydrogen. • Typically liquid at room temperature. • Often referred to as oils. • Generally come from plant sources. • There are two types. • Monounsaturated • Polyunsaturated

27. Monounsaturated Fats • Made up of fatty acid chains with one unsaturated region. • Liquid at room temperature, but solidify when refrigerated. • Become rancid more quickly than saturated fats.

28. Celebrity cook Rachael Ray popularized the use of “EVOO”: extra virgin olive oil, a monounsaturated fat.

29. Polyunsaturated Fats • Made up of fatty acid chains with two or more unsaturated regions. • Usually liquid both at room temperature and in the refrigerator. • They easily become rancid. • These fats tend to help your body get rid of newly formed cholesterol. • Sources include corn oil, soybean oil, salad dressings, mayonnaise, nuts, and seeds.

30. Polyunsaturated Fats: EFAs • Two polyunsaturated essential fatty acids (EFAs) must be obtained from your diet or supplements. • Omega-6 fatty acid (linoleic acid), obtained through plant oils, seeds, nuts. • Omega-3 fatty acid (alpha-linolenic acid), obtained through fatty fish, walnuts, flaxseed, canola oil, and green, leafy vegetables. • Both are essential to body functions. • Most people are not getting enough omega-3 fatty acids.

31. Trans Fats • Hydrogenation changes unstable, unsaturated oils into more stable, saturated solid fats called trans fats. • Less likely to turn rancid. • Occur almost exclusively in processed foods—vegetable shortening, commercially prepared baked goods, snack foods. • Found naturally in beef, lamb, and dairy products. • Foods with half a gram or less of trans fats can be labeled “trans fat free,” so check labels for hydrogenated or partially hydrogenated ingredients.

32. Trans Fats • Trans fats raise LDL cholesterol and lower HDL cholesterol, increasing the risk of heart disease. • Even small amounts can have harmful health effects. • The average American adult eats about 6 grams of trans fats per day.

33. Recommended Fat Intake • Should make up between 20 and 35% of total calories. • Trans fat intake should be kept to an absolute minimum. • Saturated fats: Less than 7% of calories, or less than 16 g (about 140 calories) for a 2,000-calorie per day diet. • Omega-6 fatty acids: About 14–17 g per day for men and about 11–12 g per day for women. • Omega-3 fatty acids: About 1.6 g per day for men and about 1.1 g per day for women.

34. Proteins • Protein is a macronutrient that helps build many body parts, including muscle, bone, skin, and blood. • Found in both animal and plant sources. • Many sources of protein are high in cholesterol and saturated fat.

35. Proteins • Recommended RDA: 10–35% of caloric intake. • Intake above or below this range increases the risk of some chronic diseases. • Few people in the U.S. suffer from protein deficiencies. • Amino acids: The building blocks of protein.

36. Amino Acids • 11 amino acids can be produced by the body. • 9 essential amino acids must be consumed from food. • Complete proteins supply amino acids all in adequate amounts. • Meat, fish, poultry, dairy products, soy • Incomplete proteins lack some essential amino acids. • Legumes, grains, vegetables, seeds • Combinations of plant proteins can yield complete proteins.

37. Amino Acids • Amino acids contribute to the following: • Antibodies, which protect you from disease. • Enzymes, which speed up chemical reactions. • Hormones, which regulate body temperature. • Transport proteins, which carry substances in and out of cells. • Buffers, which help maintain a healthy balance of acids and bases in your blood.

38. Vitamins • Substances with no energy value of their own needed by the body in small amounts for normal growth and function. • They regulate body processes such as blood-cell production, nerve function, digestion, skin and bone maintenance. • They help chemical reactions take place.

39. Vitamins • Humans need 13 vitamins. • The fat-soluble vitamins A, D, E, and K dissolve in fat and can be stored in the body’s fatty tissues. • The water-soluble vitamins dissolve in water, and excess amounts are generally excreted from the body in urine. • These include vitamin C, the B-complex vitamins thiamin, riboflavin, niacin, pantothenic acid, B6, biotin, folic acid, and B12. • Adequate amounts should be consumed daily. • Vitamin D can be manufactured in your skin with adequate sun exposure.

40. Vitamins • Vitamins can be obtained in various amounts through eating: • Fruits • Vegetables • Whole grains • Meat and dairy products • Vitamin deficiencies in those living in the U.S. are rare. • Excess consumption from supplements can lead to unpleasant side effects.

43. Minerals • Elements with no energy value of their own that regulate body processes and provide structure. • They cannot be made by living organisms. • They cannot be broken down. • Most minerals in a diet come from plants or indirectly from animal sources. • They may also be present in drinking water. • A varied diet fulfills most mineral needs. • Supplements are not recommended for most healthy people, but may be necessary for some populations.

44. Minerals • The body relies on more than a dozen essential minerals to regulate body processes and provide structure. • They help: • Adjust fluid balance. • Aid in muscle contraction and nerve transmission. • Release energy. • Provide structure for bones and teeth.

45. Minerals • Major minerals are needed by the body daily in amounts greater than 100 milligrams. • These include: • Sodium • Potassium • Chloride • Calcium • Phosphorus • Sulfur • Magnesium

46. Minerals • Trace minerals are needed by the body daily, typically in amounts less than 10 milligrams. • These include: • Iron • Fluoride • Iodine • Selenium • Zinc • Copper • Manganese • Chromium

48. Water • You can live for only a few days without water. • It is dispersed throughout the body and is vital to • Nutrient digestion. • Absorption. • Transportation • It plays an essential role in many processes. • Serves as a lubricant, regulates body temperature, carries wastes out of the body, is the medium in which most chemical reactions take place.

49. Water • Nearly all foods contain water. • Food provides about 19% of adults’ water intake. • Beverages provide the remaining 81%. • Recommendations for intake have not been established. • Most adults can maintain adequate intake through consuming water-containing foods and drinking 9 to 13 cups of beverages daily. • Some people may need additional water.

50. Fiber • A non-digestible complex carbohydrate that aids in digestion. • Softens and provides bulk for feces. • Helps promote bowel regularity. • Can aid in weight management. • Lowers blood cholesterol. • Slows the transit of food through the intestinal tract, promoting a more gradual release of glucose into the blood.