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Chapter 4

Chapter 4. Nutrition and You. 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.

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Chapter 4

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  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.

  41. 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.

  42. 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.

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

  44. 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

  45. 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.

  46. 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.

  47. 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.

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