Chapter 5: Nutrition

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

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

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

Summary:

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

Riverside’s Water – Riverside Public Utilities

http://www.ewg.org/tap-water/whats-in-yourwater.php

Riverside’s Water – Eastern Municipal Water District

http://www.ewg.org/tap-water/whats-in-yourwater.php

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

Summary:

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

● 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

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

Summary:

Fiber ● Dietary fibe r: 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 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

Summary:

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

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

Summary:

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

Summary:

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

How much FAT? ● 20-35% of your daily caloric intake

○ Less than ⅓ from saturated fats (7-10%... 22 grams)

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

Summary:

Key Vitamins and Minerals

Overview of RDIs: Recommended Daily Intakes of Macronutrients and Micronutrients

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

Summary:

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

Dietary Guidelines for Americans ● Four main goals:

○ Reduce calorie intake and increase physical activity ○ Move toward a more plant-based diet composed of

nutrientdense 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

Summary:

2010 Dietary Guidelines for Americans: Key Messages

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

Summary:

MyPlate

Estimated Calorie Requirements ----------> 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

Summary:

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

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

Nutrition Facts Food Label

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

Summary:

Recommended FOP Labels

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 equired ○ Altered label format to emphasize calories, serving

size, and Percent Daily value

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

○ 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

Summary:

Current Consumer Concerns ● Probiotics, prebiotics, and synbiotics

○ Probiotics are living bacteria that may aid digestion;prebiotics are nondigestible carbohydrates

that fuelprobiotics ○ 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

Fast-Food Meal --------->

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

Summary:

Kitchen Safety

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)

WRAP - UP

Summary: