Chapter 5 Nutrition © 2013 McGraw-Hill Education. All Rights Reserved. Understanding Nutritional Guidelines  Dietary Reference Intakes (DRIs): recommended intake levels of essential nutrients for optimal health 

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Transcript Chapter 5 Nutrition © 2013 McGraw-Hill Education. All Rights Reserved. Understanding Nutritional Guidelines  Dietary Reference Intakes (DRIs): recommended intake levels of essential nutrients for optimal health 

Chapter 5
Nutrition
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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
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2
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
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3
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
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4
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
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5
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)
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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
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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)
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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
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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
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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
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 For example, beans and rice
11
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
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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)
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13
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
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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
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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
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16
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
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17
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)
•
–
Microminerals (need less than 100 mgs/day)
•
•
Calcium, chloride, magnesium, phosphorous, potassium, sodium
Chromium, cobalt, copper, fluorine, iodine, iron, zinc, manganese, nickel, and others
A balanced diet provides all the essential minerals the body needs per day
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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
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19
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
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Dietary Guidelines for Americans
 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
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Dietary Guidelines for Americans
 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
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Dietary Guidelines for Americans

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
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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
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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-ofpackage (FOP) food labels is limited

Institute of Medicine found these labels provide little
guidance and cause confusion

Recommended a standard for FOP labels
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25
Nutrition Facts Food Label
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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
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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
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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
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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
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Kitchen Safety
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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)
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