Chapter 3

Nutrients Balancing the Diet

Nutrient Supplementation

Energy (ATP) Production

Nutrition for Athletes

Special Nutrient Needs of Women

Dietary Guidelines for Americans

Chapter 3

Nutrition for Wellness

CHAPTER

OUTLINE

Key TermsNutrition: Science that studies the relationship of foods to optimal health and performance

Nutrients: Substances found in food that provide energy, regulate metabolism, and help with growth and repair of body tissues







3.7

Calories per Gram of Food

CarbohydrateMajor source of energy (4 calories/gram)

Regulates digestion, fat, and protein metabolism

Two types:Simple

Complex







Simple CarbohydratesFormed by simple or double sugar units with little nutritive value

Divided into monosaccharides and disaccharides







Complex CarbohydratesCarbohydrates formed by three or more simple sugar molecules linked together

Also referred to as “polysaccharides”







3.2Major Types of Carbohydrates

FiberComplex carbohydrate in plant foods that cannot be digested by the human body but is essential in the digestion process

Present mainly in skins, leaves, roots, and seeds

Dietary sources includeWhole grain cereals and breads

Fruits and vegetables

Legumes







FiberLack of fiber has been linked to

Cardiovascular disease

Cancer

Constipation

Diverticulitis

Hemorrhoids

Gallbladder disease

Obesity







Recommended Amount of Fiber

Under age 50Women = 25 gr/day

Men = 38 gr/day

Over age 50Women = 21 gr/day

Men = 30 gr/day

Current average daily U.S. intakeAbout 15 gr/day







FiberTwo types

Soluble fiberDissolves in water to form gel-like substance that encloses food particles

Helps decrease blood cholesterol and blood sugar

Insoluble fiberNot easily dissolved in water but binds with water

Causes a softer and bulkier stool







FatSource of energy (9 calories/gram)

Stored energy

Part of cell structure

Insulator for body heat preservation

Shock absorption

Carries fat soluble vitamins (A, D, E, and K)







Types of Fat

Simple fatsSaturatedMonounsaturatedPolyunsaturated

Compound fatsPhospholipidsGlucolipidsLipoproteins

Derived fatsSterols (cholesterol)







3.3Major Types of Fat

3.4

Chemical Structure of Saturated and Unsaturated Fats

Key TermsTransfatty acid: Solidified fat formed by adding hydrogen to monounsaturated and polyunsaturated fats to increase shelf life

Omega-3 fatty acids: Polyunsaturated fatty acids found primarily in cold-water seafood and flaxseeds thought to lower blood cholesterol and triglycerides

Omega-6 fatty acids: Polyunsaturated fatty acids found primarily in corn and sunflower oils and most oils in processed foods







ProteinSource of energy (4 calories/gram)

Builds and repairs tissue

Part of hormones, enzymes, and antibodies

Helps maintain normal fluid balance







Vitamins and MineralsVitamins

Organic substances essential for normal metabolism, growth, and development

Fat soluble (A, D, E, and K)

Water soluble (B complex and C)







Vitamins and MineralsMinerals

Inorganic elements essential for normal body functions

Part of all cells and enzymes

Help maintain water and acid-base balance

Regulate muscle and nervous tissue excitability







3.5Approximate Proportions of Nutrients in the Human Body

Higher percentage of fat tissue in women is normal and needed for reproduction

1% Carbohydrates5% Minerals12% Protein27% Fat56% Water

1% Carbohydrates6% Minerals16% Protein

17% Fat61% Water

“Balancing the Diet

What you eat may be leading you to an early grave.”







3.1Food Guide Pyramid

Bread, Cereal, Rice,and Pasta Group6–11 SERVINGS

Fruit Group2–4 SERVINGS

Vegetable Group3–5 SERVINGS

Meat, Poultry, Fish,Dry Beans, Eggs,and Nuts Group2–3 SERVINGS

Milk,Yogurt,and Cheese Group2–3 SERVINGS

Fats, Oils, and SweetsUSE SPARINGLY

3.5The American Diet: Current and Recommended Carbohydrate, Fat, and Protein Intake Expressed as a Percentage of Total Calories

Key TermsDietary Reference Intakes (DRIs): A general term that describes four types of nutrient standards that establish adequate amounts and maximum safe nutrient intakes in the diet; these standards are

Estimated Average Requirements (EAR)Recommended Dietary Allowances (RDA)Adequate Intakes (AI)Tolerable Upper Intake Levels (UL)

Estimated Average Requirements (EAR): The amount of a nutrient that meets the dietary needs in half the people in the U.S.Recommended Dietary Allowances (RDA): The daily amount of a nutrient (statistically determined from the EARs) considered adequate to meet the known nutrient needs of almost 98% of all healthy peoplein the U.S.







Key TermsAdequate Intakes (AI): The recommended amount of a nutrient intake when sufficient evidence is not available to calculate the EAR and subsequent RDA

Upper Intake Level (UL): The highest level of nutrient intake that appears safe for most healthy people, beyond which exists an increased risk of adverse effects

Daily Values (DVs): Reference values for nutrients and food components used in food labels







Reference values for nutrients and food components for use on food labels

Include as percentage of total calories: fat, saturated fat, and carbohydrates

Include cholesterol, sodium, and potassium in milligrams

Include fiber and protein in grams

3.6

Daily Values (DVs)

3.6

Dietary Reference Intakes (DRIs): Recommended Dietary Allowances (RDA) and Adequate Intakes

Critical ThinkingWhat do the nutrition standards mean to you?

How much of a challenge would it be to apply those standards in your daily life?







Nutrient AnalysisFirst step in evaluating the diet

Most people do not realize how harmful and non-nutritious many common foods are







Nutrient AnalysisAnalysis coverscalories, carbohydrates, fats, cholesterol, and sodium

Also covers eight crucial nutrients: protein, calcium, iron, vitamin A, thiamin, riboflavin, niacin, and vitamin C

If the regular diet has enough of these eight nutrients, foods consumed in natural form typically contain all the other nutrients needed







Nutrient AnalysisMost revealing information learned in a nutrient analysis is the source of fat intake

Average daily fat consumption in the U.S. dietAbout 34% of the total caloric intake

Much of it from saturated fat and trans fatty acids, which increase the risk for chronic diseases







Calories in Fast Food

590400

540760

8501060

760350

520810

226374

450440Frosty, med.

TunaSweet Onion TeriyakiVeggie Del.Market Fresh Roast BeefRoast Chicken ClubRegular Roast BeefIce Cream Shake, med.Double WhopperWhopper w/ CheeseWhopperLarge FriesChicken McGrillBig Mac

McDonald's

Burger King

Arby’s

SubwayWendy’s







Fat Content in Fast FoodCalories Total Fat

SaturatedFat

% fatcalories

McDonald'sBig Mac 590 34 11 52Chicken McGrill 400 17 3 38Large Fries 540 26 9 43Burger KingWhopper 760 46 15 54Whopper w Cheese 850 53 22 56Double Whopper 1060 69 27 59Ice Cream Shake, med. 760 41 29 49Arby’sReguar Roast Beef 350 16 6 41Roast Chicken Club 520 28 7 48Market Fresh RoastBeef

810 42 13 47

SubwayVeggie Delight 226 3 1 12Sweet Onion Teriyaki 374 5 2 12Tuna 450 22 6 44Wendy’sFrosty, med. 440 11 7 23







Sizing Up Fast Foods

Super FoodsThe following “super” foods that fight disease and promote health should be included often in the diet

Avocados Bananas Beans Beets Blueberries Broccoli Butternut squash Carrots Grapes

Kale Kiwifruit Flaxseeds Nuts (Brazil, Walnuts)Salmon (wild)SoyOats and oatmealOlives andolive oil

OnionsOrangesPeppersStrawberriesSpinachTea (green, black, red)TomatoesYogurt







Grains, Vegetables, & FruitsProvide nutritional base for a healthy diet

Daily fruits and vegetables should includeOne good source of pro-vitamin A or carotene (apricots, cantaloupe, broccoli, carrots, pumpkin, dark leafy vegetables)

One good source of vitamin C (citrus fruit, kiwi fruit, cantaloupe, strawberries, broccoli, cabbage, cauliflower, green pepper)

The recommended 5 to 9 servings of fruits and vegetables daily has no substitute







Phytochemicals

Fruits and vegetables are the sole source of phytochemicals

Show promising results in the fight against cancer

Their actions are so diverse that, at almost every stage of cancer, they can block, disrupt, slow down, or even reverse the process







Mediterranean DietMediterraneans have lower rates of diet-linked diseases and a longer life expectancy

Although a semivegetarian diet, up to 40% of the daily caloric intake comes from fat: mostly monounsaturated fat from olive oil







The Mediterranean diet is more than just a “diet”: it is a dietary pattern that has existed for centuries

3.11

The Mediterranean Diet

Ethnic DietsAre healthier than the typical American diet

Emphasize consumption of complex carbohydrates

Limit fat intake

Become unhealthy when “Americanized”







Critical ThinkingDo you take supplements?

If so, for what purposes are you taking them—and do you feel that you could restructure your diet so that you could do without them?







Nutrient SupplementsHalf of all adults in U.S. take daily nutrient supplements

Nutrient requirements for body normally can be met by consuming 1,200 calories per day, as long as the diet contains the recommended servings from the five food groups







Nutrient SupplementsWater-soluble vitamins: The body cannot retain these vitamins as long as fat-soluble vitamins; excessive intake is excreted

Small amounts, however, can be retained for weeks or months

Fat-soluble vitamins: stored in fatty tissue; daily intake of these vitamins is not as crucial

Too much vitamin A and vitamin D can be detrimental







Nutrient SupplementsDo not take megadoses of a supplement(s)

For some nutrients, a dose of five times the RDA taken over several months may create problems

Vitamin and mineral doses should not exceed ULs

For nutrients that do not have a UL, no dosage higher than three times the RDA should be taken







AntioxidantsMuch research is being done on antioxidants for thwarting chronic diseases

Although there are over 4,000 antioxidants, the four most studied are

Vitamin C

Vitamin E

Beta-carotene (a precursor to vitamin A)

Selenium







AntioxidantsOxygen is used to change carbohydrates and fats into energy

A small amount of oxygen ends up in an unstable form, referred to as oxygen free radicals

A free radical molecule has a normal proton nucleus with a single, unpaired electron (making it extremely reactive)







AntioxidantsFree radicals attack and damage proteins and lipids

Damage is thought to contribute to the development ofCardiovascular disease, cancer, emphysema, cataracts, Parkinson's disease, premature aging

Free radical formation is enhanced bySolar radiation, cigarette smoke, air pollution, radiation, some drugs, injury or infection, chemicals (such as pesticides), and other environmental factors

Antioxidants offer protection by absorbing free radicals







AntioxidantsWhen free radicals are produced faster than the body can neutralize them, they cause damage

Antioxidants are found abundantly in food, especially in fruits and vegetables

Most Americans do not eat the minimum five daily servings of fruits and vegetables







AntioxidantsSome authors/researchers believe antioxidant supplements further prevent free radical damage

The University of California at Berkeley Wellness Letter recommends the following daily supplements:

250 to 500 mg of vitamin C

200 to 400 IU vitamin E (natural vitamin E)







AntioxidantsVitamin C: Consuming 5 or more daily servings of fruits and vegetables will provide the recommended amount

Vitamin E: Obtaining the recommended daily antioxidant amount of vitamin E through diet alone is practically impossible

May reduce the risk of heart disease in healthy people

Some research questions the benefits of vitamin E supplementation—additional research is required







Vitamin CWater-solubleBody eliminates it in about 12 hoursConsume vitamin C-rich foods twice a day ordivide the vitamin C supplement in half and take twice dailyOffers benefits against heart disease, cancer,cataracts, and several other health disordersConsume between 250 and 500 mg daily







Selenium200 micrograms (mcg) of selenium daily decreases risk of

Prostate cancer by 63%

Colorectal cancer by 58%

Lung cancer by 46%

Also breast, liver, and digestive tract cancers

Selenium may interfere with body’s absorption of vitamin C; take supplements at different times

Vitamin E supplements increase the effectiveness of selenium







SeleniumOne Brazil nut (unshelled) provides 100 mcg Shelled nuts average only about 20 mcgToo much can damage cells

If you choose to take a supplement, take organic form from yeast, not selenium selenite







MultivitaminsA multivitamin complex that provides 100% of the DV for most nutrients can help fill deficiencies

Some evidence suggests regular intake decreases risk for heart disease and stroke

Multivitamins don’t provide energy, fiber, phytochemicals, or recommended dose of vitamin C and E







3.13

In addition to antioxidants, wholesome foods contain substances not yet discovered

Many nutrients work in synergy

Top Antioxidant Foods

Key TermsFunctional foods: Foods or food ingredients containing physiologically active substances that provide specific health benefits beyond those supplied by basic nutrition







Functional FoodsCreated by the food industry by adding ingredients aimed at treating or preventing symptoms or disease

In most cases only one extra ingredient is added (a vitamin, mineral, phytochemical, or herb)







Functional FoodsAn example is calcium added to orange juice to make the claim that this particular brand offers protection against osteoporosis

Food manufacturers now offer cholesterol-lowering margarines (enhanced with plant stanol), cancer-protective (lycopene-fortified) ketchup, memory-boosting (ginkgo-added) candy, calcium-fortified chips, and kava-kava–containing corn chips (to enhance relaxation)







Key TermsGenetically modified foods (GM foods): Foods whose basic genetic material (DNA) is manipulated by inserting genes with desirable traits from one plant, animal, or microorganism into another one to either introduce new traits or enhance existing ones







GM FoodsCrops are genetically modified to make them resist disease and extreme environmental conditions, require less fertilizers and pesticides, last longer, and to improve nutrient content and taste

GM foods could help save billions of dollars in more productive crops and help feed the hungry in developing countries around the world







GM FoodsConcerns over the safety of GM foods have created heated public debates

Genetic modifications may create “transgenic” organisms that have not previously existed and that have potentially unpredictable effects on the environment and on humans

GM foods may cause illness or allergies in humans and crosspollination may destroy other plants or create “superweeds” with herbicide-resistant genes







Aerobic System

Anaerobic or Lactic Acid System

ATP and ATP-CP System

3.14

Systems to Produce Energy (ATP)

Nutrition for AthletesIn general, athletes do not require a special diet or supplements

Even in resistance training and body building, protein in excess of 20% of daily energy intake is not needed

The main difference between the diet of a sedentary person and an active person is the total caloric and carbohydrate intake due to prolonged physical training







Carbo LoadingAmount of glycogen stored in muscle tissue can be increased greatly through carbohydrate loading

Diet should be alteredDuring days of heavy aerobic training

When a person is going to participate in a long-distance event lasting longer than 90 minutes







Carbo LoadingPerformance is enhanced for long-distance events by

Following a regular diet with 50 to 60% carbs and engaging in intense physical training the 5th and 4th days before the eventFollowed by a diet high in carbs (about 70%) and a progressive decrease in training intensity over the last 3 days

The amount of glycogen stored from carbo loading is not affected by proportion of complex and simple carbohydrates







Pre-Event MealConsume 1 gram of carbohydrate for each kilogram (2.2 pounds) of body weight 1 hour prior to exercise

Can be increased to 2, 3, or 4 grams per kilogram of weight 2, 3, or 4 hours respectively before exercise







Fluid and Carbohydrate Intake During Long-Distance Events

Consume 30 to 60 grams of carbohydrates per hour

Best accomplished by drinking 8 ounces of a sports drink containing 6 to 8% carbohydrate every 15 minutes

Fluid intake lessens the chance of dehydration







CreatinePopular supplement to help increase muscle mass and improve athletic performanceSupplementation can yield up to a 20% increase in muscle creatineSupplementation is believed to enable more intense trainingTwo phases: a five-day loading phase (20–25 gr/day) and maintenance (2 gr/day)Creatine does benefit aerobic events







Amino Acid SupplementsScience has not yet proven that they help increase muscle mass

Normal increase in caloric and protein intake is enough to build and repair muscle tissue

Each capsule provides 500 mg of amino acids and no nutrients; 3 oz of meat provide 20,000 mg plus nutrients

Amino acid supplementation can cause imbalances and toxicities







Osteoporosis

A condition that leads to softening, deterioration, or loss of bone mineral density; causes disability, fractures, and even death from medical complications

About 22 million women in the U.S. suffer from this condition (16 million do not know they have it)

One in 2 women and one in 8 men will suffer from osteoporosis







Prevention of OsteoporosisMaximize bone density during youth

Maintain normal menses

Participate in a lifetime program of physical activity

Maintain adequate calcium intake throughout life

Do not smoke

Avoid corticosteroid drug use

Avoid excessive use of alcohol

See your physician following menopause







3.15Threats toBone Health

MenopauseAgeover 50

Family

history of

osteoporosis

Phys

ical

inac

tivity

Low-calciu

m

dietExtensiveuse of

corticosteroids

Smallframe

White

or Asian

Hea

vydr

inki

ngSmoking

2005 Dietary Guidelinesfor Americans

Consume a variety of foods within and among the basic food groups while staying within energy needs

Control calorie intake to manage body weight

Be physically active every day





Special Nutrient Needs

of Women

Dietary Guidelines for

Americans


Increase daily intake of fruits and vegetables, whole grains, and nonfat or low-fat milk and milk products Choose fats wisely for good health Choose carbohydrates wisely for good health






of Women


Americans


Choose and prepare foods with little salt If you drink alcoholic beverages, do so in moderation Keep food safe to eat






of Women


Americans

Critical ThinkingWhat factors in your life and the environment have contributed to your current dietary habits?

Do you need to make changes?

What may prevent you from doing so?






of Women


Americans

End of Chapter

Chapter 3

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