Transcript Document

Nutrition Basics
Chapter 9
© 2010 McGraw-Hill Higher Education. All rights reserved.
Nutritional Requirements:
Components of A Healthy Diet
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45 essential nutrients
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Proteins, fats, carbohydrates, vitamins, minerals, water,
etc
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Macronutrients
Micronutrients
Energy in food is expressed as kilocalories (called
calories in common usage)
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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:
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Fat = 9 calories per gram
Protein = 4 calories per gram
Carbohydrates = 4 calories per gram
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Figure 9.1 The digestive system
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Proteins–The Basis of Body
Structure
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Forms muscle, bone, blood, enzymes, some
hormones and cell membranes
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Building blocks of protein are amino acids
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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
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Combine 2 vegetables to make up missing amino acids
Recommended protein intake
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0.8 gram per kilogram of body weight
10-35% of total calorie intake
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Average American daily intake is 15-16% of total calories
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Fats–Essential in Small
Amounts
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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
Hydrogenation
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Fats
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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 Health
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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 possible effects on health
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Carbohydrates—An Ideal
Source of Energy
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Supplies energy to body cells
Two groups
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Simple carbohydrates
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Fruit, sugar, honey, malt, and milk
Complex carbohydrates
Grains – wheat, rye, rice, oats, barley, and millet
 Legumes – dry beans, peas, and lentils
 Tubers – potatoes and yams
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Digestion
Mouth and small intestines
 Break down into glucose
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Refined Carbohydrates Versus
Whole Grains
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All grains are whole grains before
processing and include:
Inner layer (germ)
 Middle layer (endosperm)
 Outer layer (bran)
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During processing, the germ and
bran are removed leaving just
the starchy endosperm
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Glycemic Index and Glycemic
Response
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Insulin and glucose levels rise and fall
following any meal containing
carbohydrates
Quick rise in glucose and insulin levels =
high glycemic index
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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
Intake
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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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Carbohydrates
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Important energy source
Choose foods rich in fiber
Consumption of foods and beverages
high in added sugar should be avoided
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People who eat diets high in added sugars
tend to consume more calories and less
vitamins and minerals
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Serving Sizes
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Grains - 1 slice of bread,1 small muffin
(2.5 diameter), 1 cup ready-to-eat
cereal flakes
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Vegetable – 1 cup raw leafy vegetables,
1/2 cup cooked or raw vegetables, 1/2
cup of vegetable juice
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Fruit – 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 Look
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Types of fiber
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Sources of fiber
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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
All plant substances
Recommended fiber intake
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38 grams for adult men
25 grams for adult women
Needs to come from foods, not supplements
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Vitamins—Organic
Micronutrients
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Organic (carbon-containing) substances
required in small amounts to regulate
various processes within living cells
Humans need 13 vitamins
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Functions of vitamins
Sources of vitamins
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4 fat soluble vitamins: A, D, E, and K
9 water soluble vitamins: C and 8 B-complex
Human body does not manufacture most
vitamins
Abundant in fruits, vegetables and grains
Vitamin deficiencies
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Minerals—Inorganic
Micronutrients
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Inorganic compounds that help regulate pH,
water balance, aid in growth, and help
release energy
17 essential minerals
 Major minerals – > 5 grams
 Calcium,
phosphorus, magnesium, sodium,
sulfur, sodium, potassium, and chloride
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Trace minerals – < 5 grams, need in
minute amounts
 Copper,
fluoride, iodide, iron, selenium,
and zinc
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Water—Vital but Often Ignored
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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 Food
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Antioxidants
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Reduces incidence of cancers by free radicals
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Vitamin C & E, selenium, carotenoids
Phytochemicals
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Substances that help prevent chronic
disease
Soy foods
 Cruciferous vegetables (broccoli)
 Allyl sulfides (garlic and onions)
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Dietary Reference Intakes
(DRIs)
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Standards set by Food and Nutrition Board
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Dietary Reference Intakes (DRI)
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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 Americans
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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 Americans
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Adequate nutrients within calorie needs
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Weight Management
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Overweight and obesity are a major public health
problem in the U.S.
Physical Activity
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USDA’s MyPyramid
DASH eating plan
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 Encourage
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Dietary Guidelines for Americans and
MyPyramid both emphasize eating a wide
range of foods
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Fruits and vegetables
Whole grains
Low-fat and fat-free dairy products
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Serving Sizes
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Milk -1 cup milk or yogurt, 1/2 cup ricotta
cheese, 1.5 oz natural cheese, 2 oz.
processed cheese
Meat 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 – 1 teaspoon vegetable oil or soft
margarine
Discretionary calories, solid fats, and
added sugars
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The Vegetarian Alternative
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Types of vegetarian diets
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Vegans
Lacto-vegetarians
Lacto-ovo-vegetarians
Partial vegetarians
Semivegetarians
Pescovegetarians
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Vitamin B-12
Vitamin D
Calcium
Iron
Zinc
A food plan for vegetarians
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Dietary Challenges for Special
Population Groups
Children and teenagers
 College students
 Older adults
 Athletes
 People with special health
concerns
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A Personal Plan: Making
Informed Choices About Food
Reading food labels
 Reading dietary supplement labels
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Protecting Yourself Against
Foodborne Illness
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Causes of foodborne illnesses
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Campylobacter jejuni
Salmonella
Shigella
Escherichia coli
Listeria monocytogenes
Staphylococcus
Clostridium botulinum
Norovirus
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A Personal Plan: Making Informed
Choices About Food
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Organic foods
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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
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Nutrition Basics
Chapter 9
© 2010 McGraw-Hill Higher Education. All rights reserved.