© 2010 mcgraw-hill higher education. all rights reserved. nutrition basics chapter 9

© 2010 McGraw-Hill Higher Education. All rights reserved.

Nutrition BasicsNutrition BasicsChapter 9


Nutritional Requirements: Nutritional Requirements: Components of A Healthy DietComponents of A Healthy Diet

45 essential nutrients Proteins, fats, carbohydrates, vitamins, minerals, water,

etc Macronutrients Micronutrients

Energy in food is expressed as kilocalories (called calories in common usage)

1 kilocalorie = amount of heat it takes to raise the temperature of 1 liter of fluid 1°C

2000 kilocalories (or calories) per day meets a person’s energy needs

Three essential nutrients provide energy: Fat = 9 calories per gram Protein = 4 calories per gram Carbohydrates = 4 calories per gram

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© 2010 McGraw-Hill Higher Education. All rights reserved. 3

Figure 9.1 The digestive systemFigure 9.1 The digestive system


Proteins–The Basis of Body Proteins–The Basis of Body StructureStructure

Forms muscle, bone, blood, enzymes, some hormones and cell membranes Building blocks of protein are amino acids

Nine essential amino acids Eleven nonessential amino acids Complete proteins (usually animal proteins) provide all

essential amino acids Most plant proteins are incomplete sources of amino

acids Combine 2 vegetables to make up missing amino acids

Recommended protein intake 0.8 gram per kilogram of body weight 10-35% of total calorie intake

Average American daily intake is 15-16% of total calories

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Fats–Essential in Small Fats–Essential in Small AmountsAmounts

Most concentrated source of energy Fats can be stored as usable energy Provides insulation and support for body

organs Types and sources of fats

Triglycerides - glycerol molecule with 3 fatty acids

Animal fats are primarily made of triglycerides

Unsaturated Monounsaturated Polyunsaturated Saturated

Hydrogenation5


FatsFats

Fats and oils provide the essential fatty acids needed

Total fat: 20-35% of total daily calories Saturated fat: Less than 10% of total

calories Trans fat: As little as possible Cholesterol: Less than 300 mg per day

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Fats and HealthFats and Health

Cholesterol High-density lipoprotein (HDL) = good cholesterol Low-density lipoprotein (LDL) = bad cholesterol

Saturated and trans fats pose many health hazards, including heart disease and certain types of cancers

Other fats, including monounsaturated fats and omega-3 fatty acids, can be beneficial to health

Recommended fat intake Adult men need 17 grams per day of linoleic acid

and 1.6 grams of alpha-linolenic acid Adult women need 12 grams per day of linoleic acid

and 1.1 grams of alpha-linolenic acid AMDR for total daily fat is 20-35% of daily calories

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Figure 9.2 Types of fatty acids and their Figure 9.2 Types of fatty acids and their possible effects on healthpossible effects on health


Carbohydrates—An Ideal Carbohydrates—An Ideal Source of Energy Source of Energy

Supplies energy to body cells Two groups

Simple carbohydratesFruit, sugar, honey, malt, and milk

Complex carbohydratesGrains – wheat, rye, rice, oats, barley, and milletLegumes – dry beans, peas, and lentilsTubers – potatoes and yams

DigestionMouth and small intestinesBreak down into glucose

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Refined Carbohydrates Versus Refined Carbohydrates Versus Whole GrainsWhole Grains

All grains are whole grains before processing and include:Inner layer (germ)Middle layer (endosperm)Outer layer (bran)

During processing, the germ and bran are removed leaving just the starchy endosperm

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Glycemic Index and Glycemic Glycemic Index and Glycemic ResponseResponse

Insulin and glucose levels rise and fall following any meal containing carbohydrates

Quick rise in glucose and insulin levels = high glycemic index Eating high glycemic index foods may

increase appetite May increase risk of diabetes and heart

disease Unrefined grains, fruits, vegetables and

legumes have a relatively low glycemic index

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Recommended Carbohydrate Recommended Carbohydrate IntakeIntake

130 grams needed to meet the body’s requirements for essential carbohydrates Average American eats 200-300 grams

daily Carbohydrates should make up 45-65% of

total daily calories in an adult’s diet Health agencies recommend decreased intake

of added sugars with limits between 10% of total calories or 8 teaspoons daily

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CarbohydratesCarbohydrates

Important energy source Choose foods rich in fiber Consumption of foods and beverages

high in added sugar should be avoided People who eat diets high in added sugars

tend to consume more calories and less vitamins and minerals

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Serving SizesServing Sizes

GrainsGrains -- 1 slice of bread,1 small muffin (2.5 diameter), 1 cup ready-to-eat cereal flakes

VegetableVegetable – 1 cup raw leafy vegetables, 1/2 cup cooked or raw vegetables, 1/2 cup of vegetable juice

FruitFruit – ½ cup fresh, canned, or frozen fruit, 1/2 cup 100% fruit juice, 1 small whole fruit, 1/4 cup dried fruit

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Fiber – A Closer LookFiber – A Closer Look

Types of fiber Dietary fiber: Nondigestible carbohydrates that are

naturally present in foods Functional fiber: Nondigestible carbohydrate that

has been isolated or synthesized in a lab Total fiber is the sum of both

Sources of fiber All plant substances

Recommended fiber intake 38 grams for adult men 25 grams for adult women Needs to come from foods, not supplements

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Vitamins—Organic Vitamins—Organic MicronutrientsMicronutrients

Organic (carbon-containing) substances required in small amounts to regulate various processes within living cells

Humans need 13 vitamins 4 fat soluble vitamins: A, D, E, and K 9 water soluble vitamins: C and 8 B-complex

Functions of vitamins Sources of vitamins

Human body does not manufacture most vitamins

Abundant in fruits, vegetables and grains Vitamin deficiencies

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Minerals—Inorganic Minerals—Inorganic MicronutrientsMicronutrients

Inorganic compounds that help regulate pH, water balance, aid in growth, and help release energy

17 essential mineralsMajor minerals – > 5 grams

Calcium, phosphorus, magnesium, sodium, sulfur, sodium, potassium, and chloride

Trace minerals – < 5 grams, need in minute amounts

Copper, fluoride, iodide, iron, selenium, and zinc

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Water—Vital but Often IgnoredWater—Vital but Often Ignored

You are composed of about 50-60% water Can live up to 50 days without food, but only a few

days without water Foods and fluids consumed make up 80-90% of

your daily water intake Food and Nutrition Board daily requirements

Men – 3.7 total liters of water, with 3.0 liters (13 cups) coming from beverages

Women – 2.7 total liters of water, with 2.2 (9 cups) coming from beverages

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Other Substances in FoodOther Substances in Food

Antioxidants Reduces incidence of cancers by free radicalsVitamin C & E, selenium, carotenoids

Phytochemicals Substances that help prevent chronic disease

Soy foodsCruciferous vegetables (broccoli)Allyl sulfides (garlic and onions)

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Dietary Reference Intakes (DRIs)Dietary Reference Intakes (DRIs)

Standards set by Food and Nutrition Board Dietary Reference Intakes (DRI)

Recommended Dietary Allowances (RDA) Adequate Intake (AI) Tolerable Upper Intake Level (UL)

Standards aim to prevent nutrient deficiencies, promote health, and prevent chronic diseases

Daily Values are used on food labels and reflect daily guidelines for a 2,000-calorie diet

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Dietary Guidelines for AmericansDietary Guidelines for Americans

Eat a variety of nutrient-dense foods Control calorie intake to manage body weight Be physically active every day Eat plenty of grains, vegetables, and fruits Choose fats wisely Choose carbohydrates wisely Prepare foods with little salt Moderation of alcohol consumption Keep foods safe to eat

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Dietary Guidelines for AmericansDietary Guidelines for Americans

Adequate nutrients within calorie needs USDA’s MyPyramid DASH eating plan

Weight Management Overweight and obesity are a major public health

problem in the U.S. Physical Activity

Regular physical activity improves fitness, helps manage weight, promotes well-being, and reduces the risk of chronic diseases

Limit salt and alcohol intake

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Food Groups to EncourageFood Groups to Encourage

Dietary Guidelines for Americans and MyPyramid both emphasize eating a wide range of foodsFruits and vegetablesWhole grainsLow-fat and fat-free dairy products

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Serving SizesServing Sizes Milk Milk -1 cup milk or yogurt, 1/2 cup ricotta

cheese, 1.5 oz natural cheese, 2 oz. processed cheese

Meat and BeansMeat and Beans – 1 ounce cooked lean meat, 1/4 cup cooked dry beans or tofu, 1 egg, 1 tablespoon peanut butter, 1/2 ounce nuts or seeds

Oils – Oils – 1 teaspoon vegetable oil or soft margarine

Discretionary calories, solid fats, and Discretionary calories, solid fats, and added sugarsadded sugars

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The Vegetarian AlternativeThe Vegetarian Alternative

Types of vegetarian diets Vegans Lacto-vegetarians Lacto-ovo-vegetarians Partial vegetarians Semivegetarians Pescovegetarians

A food plan for vegetarians Vitamin B-12 Vitamin D Calcium Iron Zinc

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Dietary Challenges for Special Dietary Challenges for Special Population GroupsPopulation Groups

Children and teenagersCollege studentsOlder adultsAthletesPeople with special health

concerns

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A Personal Plan: Making A Personal Plan: Making Informed Choices About FoodInformed Choices About Food

Reading food labelsReading dietary supplement

labels

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Protecting Yourself Against Protecting Yourself Against Foodborne IllnessFoodborne Illness

Causes of foodborne illnesses Campylobacter jejuni Salmonella Shigella Escherichia coli Listeria monocytogenes Staphylococcus Clostridium botulinum Norovirus

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Organic foods Concerned about pesticides and other

environmental contaminants Must meet strict USDA guidelines

Additives in food Food irradiation Genetically modified foods Food allergies and food intolerances

A Personal Plan: Making Informed A Personal Plan: Making Informed Choices About FoodChoices About Food

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Nutrition BasicsNutrition BasicsChapter 9

© 2010 mcgraw-hill higher education. all rights reserved. nutrition basics chapter 9

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