Transcript Slide 1

Chapter 9 Lecture
Health: The Basics
Tenth Edition
Eating for a
Healthier You
OBJECTIVES
• Describe the factors that influence decisions about
nutrition.
• List the six classes of nutrients, and explain the primary
functions of each and their roles in maintaining long-term
health.
• Discuss how to eat healthfully, including what is a
healthful diet, how to use the MyPlate plan, information
about supplement use, and reading food labels.
• Discuss the unique challenges that college students face
when trying to eat healthy foods and the actions they can
take to eat healthfully.
• Explain food safety concerns facing Americans and
people in other regions of the world.
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Healthy Eating: An Overview
• Hunger: The physiological impulse to seek food,
prompted by the lack or shortage of basic foods needed
to provide the energy and nutrients needed to support
health
• Nutrients: The constituents of food that sustain humans
physiologically: proteins, carbohydrates, fats, vitamins,
minerals, and water
• Appetite: The desire to eat normally accompanies
hunger but is more psychological than physiological
• Nutrition: The science that investigates the relationship
between physiological function and the essential
elements of foods eaten
• Digestive Process: The process by which the body
breaks down foods and either absorbs or excretes them
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The Digestive Process
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Essential Nutrients for Health
• Calorie: A unit of measure that indicates
the amount of energy obtained from a
particular food
• Kilocalorie: 1 kilocalorie is equal to 1,000
calories.
• Most nutrition labels use the word calories
to refer to kilocalories.
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Water: A Crucial Nutrient
• Humans can survive longer without food than
without water.
• Dehydration can cause serious problems
within hours, and death within a few days.
• Too much water, hyponatremia, is also a
serious health risk characterized by low
sodium levels.
• The body consists of 50–60% water by
weight.
• Water is obtained through foods and
beverages that are consumed.
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Proteins
• After water, proteins are the most abundant substances
in the body.
– Used to repair bone, muscle, skin and blood cells, and are key
elements of antibodies.
– Proteins help transport iron, oxygen, and nutrients to all body
cells.
• Structure and Sources of Proteins
– Amino acids are the building blocks of proteins; 9 of the 20 are
essential because they must be obtained from food; the other 11
can be produced by the body.
– Dietary protein that supplies all 9 essential amino acids is known
as complete (high-quality) protein.
– Proteins from plant sources lack one or more amino acids and
are known as incomplete proteins.
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Complementary Proteins
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How Much Protein Do I Need?
• Few Americans suffer from protein
deficiency.
• The average American consumes more
than 78 grams of protein daily, mostly from
animal sources.
• Recommended intake is only 0.8 grams
protein per kilogram of body weight.
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Carbohydrates
• Are the best fuel source and provide energy
quickly and efficiently.
• Carbohydrates supply energy needed to
sustain normal daily activity. They are
metabolized faster and more efficiently than
protein.
• Carbohydrates are converted to glucose.
• They play an important role in the functioning
of the internal organs, the nervous system,
and muscles and are the best fuel for
endurance athletes.
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Forms of Carbohydrates
• Simple Carbohydrates
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Glucose (monosaccharide)—most common form
Fructose (monosaccharide)—fruit sugar
Sucrose (disaccharide)—granulated table sugar
Lactose (disaccharide)—milk sugar
Maltose (disaccharide)—malt sugar
• Complex Carbohydrates
(polysaccharides)
• Starches—grains, cereals, and vegetables
– Stored in the body as glycogen
• Fiber—"bulk" or "roughage"
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Fiber
• Insoluble
• Found in bran, whole-grain breads, and most fruits
and vegetables
• Found to reduce risk of several forms of cancer
• Soluble
• Found in oat bran, dried beans, and some fruits
and vegetables
• Helps lower blood cholesterol levels
• Helps reduce risk of cardiovascular disease
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Whole Grains versus Refined Grains
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What Carbohydrates Should I Eat? Which
Should I Avoid?
• Whole grains and high-fiber diets can
protect against obesity, colon and rectal
cancers, heart disease, constipation, and
perhaps type II diabetes.
• Choose foods such as brown rice, wheat,
bran, and whole grain breads and cereals.
• Increase fiber intake to 20–35 grams per
day.
• Eat fewer refined carbohydrates.
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ABC News Video: How Much Sugar?
Discussion Questions
1. What is the triple threat from consuming
too much added sugar?
2. What are three tips for cutting out added
sugar in your diet?
3. What are the health benefits of cutting
out extra sugar from your diet?
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Fats (Lipids)
• Misunderstood but a vital group of basic nutrients that do the
following:
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Maintain healthy skin
Insulate body organs
Maintain body temperature
Promote healthy cell function
Carry fat-soluble vitamins A, D, E, and K
Supply a concentrated form of energy
• Triglycerides make up 95% of total body fat.
– When we consume too many calories from any source, the liver
converts the excess into triglycerides, which are stored throughout our
bodies.
• Cholesterol makes up 5% of total body fat.
– Can accumulate on inner walls of arteries and contribute to
cardiovascular disease.
– Ratio of cholesterol HDL/LDL helps determine risk for heart disease.
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Fat and Trans Fatty Acid
• Types of Dietary Fat
– Saturated are mainly from animal sources and are
solid at room temperature.
– Unsaturated generally come from plants and are
usually liquid at room temperature.
• Avoiding Trans Fatty Acid
– Created by process of making liquid oil into a solid.
– Increases LDL levels while lowering HDL levels.
• Eating trans fat increases risk of coronary and heart
disease and sudden cardiac death.
– Found in many margarines, baked goods, and
restaurant deep-fried foods.
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Percentages of Saturated, Polyunsaturated,
Monounsaturated and Trans Fats in
Common Vegetable Oils
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Is More Fat Ever Better?
• Moderation is key. No more than 7 to 10%
of your total calories should come from
saturated fat and no more than 35%
should come from all forms of fat.
– Eat fatty fish.
– Use healthier oils (including olive oil).
– Eat green, leafy vegetables.
– Eat walnuts and use walnut oil.
– Eat ground flaxseed.
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Essential Nutrients for Health
• To Reduce Your Overall Intake of Less
Healthy Fats
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Read food labels.
Use olive oil for cooking.
Chill soups and stews and scrape off any fat that hardens.
Hold the creams and sauces.
Fill up on fruits and vegetables.
Avoid margarine with trans fatty acids.
Choose lean meat, fish, and poultry.
Eat fewer cold cuts and less bacon, sausages, hot dogs,
and organ meats.
– Choose nonfat dairy products.
– Use substitutes for higher-fat products.
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ABC News Video: Which Fish Is Safest to
Eat?
Discussion Questions
1. What types of fish have high levels of
mercury and should be avoided by
children and pregnant women?
2. What types of fish are lower in mercury
and are safer to eat?
3. What is the greatest health danger of
consuming too much mercury in your
diet?
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Vitamins
• Potent, essential, organic compounds
• Promote growth and help maintain life and
health
• Two Types
– Fat soluble—absorbed through intestinal tract with
the help of fats. A, D, E, and K vitamins are fat soluble
and tend to store in the body. Toxic accumulations
may cause cirrhosis-like symptoms.
– Water soluble—dissolve in water. B-complex
vitamins and vitamin C are water soluble. These are
generally excreted and cause few toxicity problems.
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Antioxidants
• Antioxidants
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Often in functional foods
Most common are vitamin C, vitamin E, and beta-carotene.
Free radicals damage or kill healthy cells.
Antioxidants scavenge free radicals, slow their formation, and
repair oxidative stress damage.
• Carotenoids
– Lycopene (in tomatoes, papaya, pink grapefruit, and guava)
reduces the risk of cancer.
– Lutein (in green leafy vegetables, spinach, broccoli, kale, and
brussels sprouts) protects the eyes.
• Vitamin D
– Formed when skin is exposed to the sun.
– Improves bone strength, helps fight infections, lowers blood
pressure.
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Minerals
• Inorganic, indestructible elements that aid the
body
– Vitamins cannot be absorbed without minerals
• Major minerals are needed in large amounts.
– Sodium, calcium, phosphorus, magnesium,
potassium, sulfur, and chloride
• Trace minerals are needed in small amounts.
– Iron, zinc, manganese, copper, and iodine
– Excesses or deficiencies of trace minerals can cause
serious problems.
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Sodium and Calcium
• Sodium
– Necessary for regulation of blood and body fluids,
transmission of nerve impulses, heart activity, and certain
metabolic functions.
– Recommended consumption less than 1 teaspoon of table
salt per day
• Calcium
– Plays a vital role in building strong bones and teeth,
muscle contraction, blood clotting, nerve impulse
transmission, regulating heartbeat, and fluid balance within
cell.
– Most Americans do not consume the recommended
amount of 1,000 to 1,200 mg/day.
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Iron
• The most common nutrient deficiency globally
• Women aged 19 to 50 need about 18 mg per
day.
• Men aged 19 to 50 need about 10 mg.
• Iron-deficiency anemia—body cells receive
less oxygen, and carbon dioxide wastes are
removed less efficiently.
• Iron toxicity—ingesting too many ironcontaining supplements
• Men who consume excess iron have a higher
risk of gallstones.
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DRIs: Recommended Intakes for Nutrients
• Dietary Reference Intake (DRIs): a list of 26 nutrients
essential to maintaining health
• Recommended Daily Allowances (RDAs): the reference
standard for intake levels necessary to meet the nutritional
needs of 97–98% of healthy individuals
• Adequate Intake (AI): the recommended average daily
nutrient intake level when there is not enough research to
determine the full RDA
• Tolerable Upper Intake Level (UL): the highest amount of a
nutrient that an individual can consume daily without risk of
adverse effects
• Acceptable Macronutrient Distribution Range (AMDR): the
range of intakes for carbohydrates, fat, and protein associated
with a reduced risk of chronic disease, that provides adequate
levels of essential nutrients
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How Can I Eat More Healthfully?
• What Is a Healthful Diet?
– A healthful diet should be
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Adequate
Moderate
Balanced
Varied
Nutrient dense
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Trends in Per Capita Nutrient Consumption
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Dietary Guidelines for Americans, 2010
• MyPlate plan
• Balance calories
– Enjoy your food, but eat less.
– Avoid oversized portion.
• Foods to increase
– Make half your plate fruits and vegetables.
– Make at least half your grains whole.
– Switch to fat-free or 1% milk.
• Foods to reduce
– Compare sodium in foods such as soup, bread, and
frozen meals – choose foods with lower numbers.
– Drink water instead of sugary drinks.
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MyPlate Plan
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How Can I Eat More Healthfully? (cont.)
• Understand serving sizes
• Eat nutrient-dense foods
• Reduce empty calorie foods
– Cakes, cookies, pastries, and donuts
– Sodas, energy drinks, sports drinks, and fruit
drinks
– Cheese
– Pizza
– Ice Cream
• Physical activity
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Serving Size Card
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Read the Labels
• % Daily Value (%DV)
• Other claims include
– Nutrient content claims
– Structure and function claims
– Dietary guidance claims
– Qualified health claims
– Health claims
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Reading a Food Label
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Vegetarianism: A Healthy Diet?
• Strict vegetarians, or vegans, avoid all food of
animal origin.
• Lacto-vegetarians eat dairy products but avoid flesh
foods and eggs.
• Ovo-vegetarians add eggs to the vegan diet.
• Lacto-ovo vegetarians eat both dairy products and
eggs.
• Pesco-vegetarians eat fish, dairy products, and
eggs.
• With proper information and food choices,
vegetarianism provides a superb alternative to meatbased cuisine.
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Supplements: Research on the Daily Dose
• Dietary Supplements
– Products taken by mouth to supplement
existing diets
– Include vitamins, minerals, and herbs
– FDA does not evaluate supplements prior to
their marketing; companies are responsible
for their own monitoring.
– A multivitamin added to a balanced diet will
generally do more good than harm.
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Eating Well in College
• If you must eat fast food
– Ask for nutritional analyses of items.
– Order salads, but be careful about what you add to
them.
– Avoid lard-based or other saturated-fat products and
trans fats.
– Avoid giant-sized portions, and refrain from ordering
extras.
– Limit beverages and foods high in added sugars.
– At least once per week, add a vegetable-based meat
substitute into your fast-food choices.
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ABC News Video: You Are What You Eat
Discussion Questions
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Do you think it is a good idea for restaurants to post
calorie content for the food on their menus? Would
knowing the calorie content of a particular food keep
you from ordering it?
What are the goals of including calorie content of foods
on restaurant menus?
Why are "healthy" options in danger of being removed
from restaurant menus?
How can restaurants respond responsibly to
progressive laws such as the one requiring the posting
of calorie information on menus?
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Eating Well in College (cont.)
• In the dining hall try this
– Choose lean meats, grilled chicken, fish or vegetable
dishes. Avoid fried foods.
– Hit the salad bar and pick leafy greens, beans, tuna or
tofu, and avocados or nuts.
– Choose baked potatoes with salsa, or add grilled chicken
to your salad.
– At the made-to-order section, hold the butter, mayonnaise,
sour cream or cheese, or cream-based sauces.
– Avoid seconds, and pass on high-calorie, low-nutrient
sweets.
– Ask the food services manager about providing additional
healthy options.
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Is Organic for You?
• Organic foods are those grown or raised
without the use of synthetic pesticides,
chemicals, or hormones.
• A review of published literature found no
evidence that organic foods are
nutritionally better than traditionally grown
foods.
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ABC News Video: Going Green
Discussion Questions
1. What relationship exists between the
loss of local farmland and the quality of
food in supermarkets?
2. What is the primary goal of green
markets?
3. What are some benefits of purchasing
food at green markets?
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Food Safety: A Growing Concern
• Food-borne pathogens sicken over 48 million
people and cause 128,000 hospitalizations
and 3,000 deaths per year.
• Signs of food-borne illness
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Cramping
Nausea
Vomiting
Diarrhea
• Symptoms occur from 30 minutes after eating
to several days or weeks later.
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Contributing Factors to the Increase in
Food-borne Illnesses
• Moving to a heart-healthy diet has spurred demand for
fresh foods not in season most of the year. About 70% of
fruits and vegetables eaten here come from Mexico.
• Food can be contaminated by tainted water, animal
fertilizers, by people who have not washed their hands
properly after using the toilet, or because the food was
not subjected to the rigorous pesticide standards in the
United States.
• Introduction of pathogens to new geographic regions
• Insufficient education about food safety
• Globalization of the food supply, climate change, and
global warming
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Avoiding Risks in the Home
• Unsafe handling of food in the home results in
more than 30% of all foodborne illnesses.
• To reduce risk
– Wash hands, and wash all produce before eating.
– Avoid cross-contamination by using separate cutting
boards and utensils.
– Ensure refrigerators are set to 40 degrees or less.
– Cook meats to recommended temperatures.
– Keep hot foods hot and cold foods cold.
– Eat leftovers within 3 days; when in doubt, throw it
out.
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Food Sensitivities
• Food Allergies
– Abnormal response to a food triggered by the immune system
– Symptoms include rapid breathing or wheezing, hives, rash,
eczema, runny nose, facial swelling, or respiratory problems
(anaphylactic reaction).
– In 2004, Congress passed the Food Allergen Labeling and
Consumer Protection Act (FALCPA), which requires food
manufacturers to clearly label foods containing ingredients that are
common allergens.
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Less dramatic reaction than food allergies
Not the result of immune system response
Generally show as gastric upset
Lactose intolerance is common and also happens in response to
food additives (MSG, sulfites, gluten).
– May have psychological triggers
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Genetically Modified Food Crops
• Genetic modification involves the insertion
or deletion of genes into the DNA of an
organism.
• About 75% of the soy and about 40% of
the corn used in processed foods are
genetically modified.
• The World Health Organization states that
no effects on human health have been
shown from the consumption of GM foods.
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