chapter 5 nutrition © 2013 mcgraw-hill education. all rights reserved.1

Chapter 5

Nutrition

© 2013 McGraw-Hill Education. All Rights Reserved. 1

Understanding Nutritional Guidelines

• Dietary Reference Intakes (DRIs): recommended 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


Understanding Nutritional Guidelines

• USDA MyPlate: graphic nutritional tool developed to accompany the 2010 Dietary Guidelines for Americans

• 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


Types of Nutrients

• Essential nutrients: needed to build, maintain, and repair tissues and regulate body functions

• Macro-nutrients: needed in large amounts– Water, carbohydrates, proteins, fats

• Micro-nutrients: needed in small amounts– Vitamins, minerals

– Calorie: measure of energy provided by food– 9 calories per gram of fat– 4 calories per gram of carbohydrates and proteins


Water—The Unappreciated Nutrient

• Function:– Digests, absorbs, transports nutrients– Helps regulate body temperature– Carries waste out of the body– Lubricates our body parts

• 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


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)


Simple and Complex Carbohydrates

• Simple carbohydrates:– Easily digestible and composed of one or two

units of sugar• Glucose, fructose, galactose, lactose, maltose,

sucrose

• Complex carbohydrates:– Sources:

• Whole grains (whole wheat, brown rice, oatmeal, corn)

• Vegetables

• Some fruit


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

• RDA:– 25 grams/day for women (aged 19-50)– 38 grams/day for men (aged 14-50)


Fiber

• 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


Protein—Nutritional Muscle

• Function:– Build and maintain muscles, bones, and other

body tissues– Form enzymes that facilitate chemical reactions

• Types:– Complete proteins– Incomplete proteins

• RDA:– 0.36 grams per pound of body weight


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


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 one-

third coming from saturated fats


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)


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


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


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


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


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


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


Key Vitamins and Minerals


Key Vitamins and Minerals

Overview of RDIs


Overview of Recommended Daily Intakes

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– Phytonutrients: may inhibit growth of cancer and

heart disease


The Color Wheel of Foods


The color wheel of foods.

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



• 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


2010 Dietary Guidelines for Americans: Key Messages


2010 Dietary Guidelines for Americans: Key Messages


• 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


Estimated Calorie Requirements


Estimated Calorie Requirements at Three Levels,by Age and Gender


• MyPlate: visual icon designed to raise awareness and health literacy about the different food groups

• 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


MyPlate


The USDA MyPlate.

Planning a Vegetarian Diet

• 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


Daily Values and 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

• 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– Recommended a standard for FOP labels


Nutrition Facts Food Label


Nutrition Facts panel on a food label.

Recommended FOP Labels


How front-of-package labeling works.

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


Current Consumer Concerns

• Overconsumption of soft drinks• High-sodium diets• Food allergies and food intolerances

– 7% of children, 2% of adults have food allergies– Food intolerances such as lactose intolerance are

less severe

• Overconsumption of energy bars, energy drinks, and relaxation drinks

• Fast foods


Fast-Food Meal


A fast-food meal compared with recommendeddaily intakes.

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

• 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


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


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


Kitchen Safety


Food safety in the kitchen.

Rules for Leftovers


Rules for leftovers.

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• 60% of processed foods in supermarkets

contain one or more GM ingredient• Safety assessed by FDA’s Center for Food

Safety and Applied Nutrition (CFSAN)


chapter 5 nutrition © 2013 mcgraw-hill education. all rights reserved.1

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