Chapter 5 Nutrition Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 1 Understanding Nutritional Guidelines • Dietary Reference Intakes (DRIs): umbrella term for four sets of dietary recommendations – Suggested intake levels of essential nutrients for optimal health • Recommended Dietary Allowance (RDA): represents the average daily amount of any one nutrient to protect against nutritional deficiency • Acceptable Macronutrient Distribution Range (AMDR): intake levels of essential nutrients that provide adequate nutrition and reduce risk of chronic disease Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 2 Understanding Nutritional Guidelines • Dietary Guidelines for Americans: scientifically based diet and exercise recommendations • USDA MyPlate: graphic nutritional tool that translates DRIs and Dietary Guidelines into healthy food choices • Daily Values: standards used on food labels to indicate how a particular food contributes to the recommended daily intake of major nutrients in a 2,000-calorie diet Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 3 Types of Nutrients • Essential nutrients: needed to build, maintain, and repair tissues and regulate body functions • Macronutrients: needed in large amounts – Water, carbohydrates, proteins, fats • Micronutrients: needed in small amounts – Vitamins, minerals Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 4 Water—The Unappreciated Nutrient • Function: – – – – Digests, absorbs, transports nutrients Helps regulate body temperature Carries waste out of the body Lubricates our body parts • Fluid balance: right amount of fluid inside and outside each cell; maintained by electrolytes Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 5 Water—The Unappreciated Nutrient • In most places in U.S. tap water is of equal or superior quality to bottled water • RDA: – 1 to 1.5 milliliters per calorie spent – 2 to 3 liters, or 8 to 12 cups of fluid – Water needs can vary depending on several factors, such as foods consumed and activity level Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 6 Carbohydrates—Your Body’s Fuel – The body’s main source of energy – Fuel most of the body’s cells during daily activities – Used by muscle cells during high-intensity exercise – Only source of energy for brain cells, red-blood cells, and some other types of cells • Types: – Simple carbohydrates (sugars) – Complex carbohydrates (starches and dietary fibers) • RDA: – 130 grams for males and females (aged 1–70) Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 7 Simple and Complex Carbohydrates • Simple carbohydrates: – Easily digestible and composed of one or two units of sugar • Glucose, fructose, galactose, lactose, maltose, sucrose • Glucose travels to liver where it can be stored as glycogen for future energy needs • Too many simple carbohydrates leaves you with a “sugar high”, followed by a feeling of depletion, and a craving for more sugar – Added sugars have even more dramatic effect – High fructose corn syrup (HFCS) • Artificial sweeteners touted as alternative – Safety concerns; effect on appetite and insulin Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 8 Simple and Complex Carbohydrates • Complex carbohydrates: – Composed of multiple sugar units including starches and dietary fiber – Sources: • Whole grains (whole wheat, brown rice, oatmeal, corn) • Vegetables; some fruit – Whole grains preferred over refined carbohydrates (white flour products) • Provide more nutrients • Slow digestive process • Make you feel full longer Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 9 Fiber • Dietary fiber: complex carbohydrate found in plants that cannot be broken down by the digestive tract • Fiber allows for passage of food quickly through the intestines, which helps prevent hemorrhoids and constipation • Soluble fiber dissolves in water and lowers cholesterol • Insoluble fiber passes through digestive tract unchanged; serves as natural laxative Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 10 Fiber • RDA: – 25 grams/day for women (aged 19-50) – 38 grams/day for men (aged 14-50) • Fiber is best obtained through diet, not pills or supplements • Sources of fiber: – – – – – – – – Fruits Vegetables Dried beans Peas and other legumes Cereals Grains Nuts Seeds Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 11 Protein—Nutritional Muscle • Function: – Build and maintain muscles, bones, and other body tissues – Form enzymes that facilitate chemical reactions – Constructed from 20 different amino acids • Essential amino acids must be supplied by foods • Types: – Complete proteins – Incomplete proteins • RDA: – 0.36 grams per pound of body weight Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 12 Protein—Nutritional Muscle • Complete protein sources – Animal proteins: meat, fish, poultry, milk, cheese, eggs • Incomplete protein sources – Vegetable proteins: grains, legumes, nuts, seeds, other vegetables • Complementary proteins: proteins that in combination provide essential amino acids • Mutual supplementation: nutritional strategy of combining two incomplete protein sources to provide a complete protein – For example, beans and rice Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 13 Fats—A Necessary Nutrient • Principal form of stored energy in the body – Provide essential fatty acids – Role in the production of other fatty acids and Vitamin D – Provide the major material for cell membranes and for the myelin sheaths that surround nerve fibers – Assist in absorption of fat-soluble vitamins – Affect texture, taste, and smell of foods – Provide emergency reserve when we are sick or when our food intake is diminished • RDA: – 20–35% of calories from fat with only about onethird coming from saturated fats Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 14 Types of Fat • Saturated fat: found in animal products and other fats that remain solid at room temperature – – – – – – Beef Pork Poultry Whole-milk dairy products Certain tropical oils (coconut and palm) Certain nuts (macadamia) Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 15 Types of Fat • Monounsaturated fat: found primarily in plant sources, are liquid at room temperature, and are semisolid or solid when refrigerated – Olive, safflower, peanut and canola oils – Avocados – Many nuts • Polyunsaturated fat: commonly referred to as “oil”; liquid at room temperature and when refrigerated – Corn and soybean oils – Fish, including trout, salmon, and anchovies Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 16 Cholesterol • A waxy substance that is needed for several important body functions • The body produces it from the liver and obtains it from animal food sources (meat, cheese, eggs, milk) • Too much cholesterol can clog arteries and lead to cardiovascular disease • LDLs (low density lipoproteins) are the “bad” cholesterol, while HDLs (high density lipoproteins) are considered “good” • Recommended: consume no more than 300 milligrams per day Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 17 Trans Fats • Liquid vegetable oils that have been chemically changed through the process of hydrogenation to extend the shelf life of processed foods • Pose a risk to cardiovascular health by raising LDL levels and lowering HDL levels • Foods high in trans fatty acids include: – – – – Crackers, cookies, chips Cakes and pies Doughnuts Deep fried foods like French fries Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 18 Omega-3 and Omega-6 Fatty Acids • Omega-3s: contain alpha-linolenic acid, which helps slow the clotting of blood, improves arterial health, and lowers blood pressure • Omega-6s: contain linolenic-acid and are important to health, though they are often consumed too much by Americans Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 19 Minerals—A Need for Balance • Minerals are naturally occurring substances needed by the body in small amounts – Build strong bones and teeth, and help carry out metabolic processes and body functions • The body needs 20 essential minerals – Macrominerals (need at least 100 mgs/day) • Calcium, chloride, magnesium, phosphorous, potassium, sodium – Microminerals (need less than 100 mgs/day) • Chromium, cobalt, copper, fluorine, iodine, iron, zinc, manganese, nickel, and others • A balanced diet provides all the essential minerals the body needs per day Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 20 Vitamins—Small But Potent Nutrients • Naturally occurring organic substances needed by the body in small amounts • Serve as catalysts for releasing energy from carbohydrates, proteins, and fats while maintaining other body components • Your body needs at least 11 specific vitamins – A, C, D, E, K, and the B-complex vitamins • Vitamins can be found in a variety of foods, so often supplements are unnecessary Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 21 Key Vitamins and Minerals Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 22 Overview of RDIs Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 23 Other Substances in Food: Phytochemicals • Phytochemicals: substances naturally produced by plants • May keep cells healthy, slow tissue degeneration, prevent carcinogens, reduce cholesterol, protect heart, maintain hormone levels, keep bones strong • Three important types of phytochemicals: – Antioxidants: neutralize free radicals – Phytoestrogens: lower cholesterol and reduce risk of heart disease – Phytonutraceuticals: may inhibit growth of cancer and heart disease Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 24 The Color Wheel of Foods Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 25 Dietary Guidelines for Americans • Two-thirds of Americans are now overweight or obese • Focus is on stopping and reversing the spread of overweight and obesity • Approaches to change: – Individual – Environmental – Food supply Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 26 Dietary Guidelines for Americans • Four main goals: – Reduce calorie intake and increase physical activity – Move toward a more plant-based diet composed of nutrient-dense foods – Reduce intake of foods containing added sugars and solid fats and reduce overall sodium and refined grain consumption – Meet the 2008 Physical Activity Guidelines provided by the U.S. Department of Health and Human Services Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 27 2010 Dietary Guidelines for Americans: Key Messages Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 28 Dietary Guidelines for Americans • MyPlate: visual icon designed to raise awareness and health literacy about the different food groups – Emphasize foods high in nutrient density • Individual calorie requirements are calculated based on sex and age at three activity levels: – Sedentary: only light physical activity – Moderately active: equivalent to walking 1.5 miles per day at 3–4 mph – Active: more than 3 miles per day at 3–4 mph Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 29 MyPlate Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 30 Estimated Calorie Requirements Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 31 Dietary Guidelines for Americans • DASH Eating Plan: Dietary Approaches to Stop Hypertension • Recommendations for specific groups – – – – – Children and adolescents Older adults Pregnant and breastfeeding women Overweight adults and children People with chronic conditions • Limit red meat consumption – Link to heart disease, cancer, and diabetes Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 32 Vegetarian Diets • Vegetarian diets may offer protection against obesity, heart disease, high blood pressure, diabetes, digestive disorders, and some forms of cancer • Vegetarians need to make sure their diets provide the energy intake and food diversity necessary to meet dietary guidelines Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 33 Daily Values on Food Labels • FDA regulates food labels – List serving size and number of servings – Give total calories and calories from fat • Look for foods with no more than 30 percent of their calories from fat – Show how much the food contributes to Daily Values for important nutrients – Shows % of Daily Value: recommended daily intake of specified nutrients Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 34 Nutrition Facts Food Label Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 35 Front-of-Package Food Labels • FDA’s authority to regulate health claims on front-of-package (FOP) food labels is limited – Institute of Medicine found these labels provide little guidance and cause confusion • 12 different symbols, logos, and icons – Recommended a standard for FOP labels Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 36 Recommended FOP Labels Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 37 Proposed Changes to the Nutrition Facts Label • 2014 proposed changes to Nutrition Facts label for packaged food – Mandated inclusion of information on added sugars – Updated reference amounts – Specified calorie and nutrition information based on whole package not just serving size – Information on potassium and vitamin D in packaged food required – Altered label format to emphasize calories, serving size, and Percent Daily value Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 38 Restaurant Menu Labels • 2010 Patient Protection and Affordable Care Act includes new requirement: all chain restaurants provide calorie labeling on their menus • Preliminary research suggests consumers are no more likely to choose healthier menu items Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 39 Current Consumer Concerns • Overconsumption of soft drinks • High-sodium diets • Food allergies and food intolerances – Eight foods responsible for 90% of allergies: milk, eggs, peanuts, tree nuts, shellfish, soy, and wheat – Food intolerances such as lactose intolerance are less severe • Gluten-free diets – Celiac disease: immune reaction to gluten which is found in wheat, barley, rye, and triticale • Overconsumption of energy bars and energy drinks Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 40 Current Consumer Concerns • Probiotics, prebiotics, and synbiotics – Probiotics are living bacteria that may aid digestion; prebiotics are nondigestible carbohydrates that fuel probiotics – Synbiotics combine the two – Scientific studies have not confirmed health benefits • Fast foods • Food deserts: low-income areas where more than 500 people or 33% have low access to a supermarket – When fresh produce not available, people don’t have opportunity to choose a healthy diet Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 41 Fast-Food Meal Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 42 Organic Foods • Plant foods grown without synthetic pesticides or fertilizers • Animal foods raised on organic feed without antibiotics or growth hormone • USDA regulates labeling • Research has not demonstrated health benefits, but environmental benefits are clear – Look for foods that are not only organic but also locally grown – Wash organic produce thoroughly Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 43 Foodborne Illnesses • Food intoxication: food poisoning in which food is contaminated by natural toxins – Botulism • Food infection: food poisoning in which food is contaminated by disease-causing microorganisms, or pathogens – E. coli, salmonella, campylobacter – Pet food can contain salmonella • Use safe food practices and store food safely, especially leftovers Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 44 Kitchen Safety Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 45 Genetically Modified Foods • Genetically modified (GM) organisms: genetic makeup has been changed to produce desirable results – Selective breeding – Modern biotechnology faster and more refined • Many crops are already GM • Sixty percent of processed foods in supermarkets contain one or more GM ingredient • Safety assessed by FDA’s Center for Food Safety and Applied Nutrition (CFSAN) Copyright © 2015 McGraw-Hill Education. All rights reserved. No reproduction or distribution without the prior written consent of McGraw-Hill Education. 46