Nutrition.ppt

9
PowerPoint® Lecture Outlines prepared by
Dr. Lana Zinger, QCC  CUNY
Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings.
Nutrition: Eating
for Optimum
Health

Assessing Eating Behaviors
 What drives us to eat?
• Hunger
• Appetite
• Cultural and social meaning of food
• Habit or custom
• Emotional Comfort
• Convenience and advertising
• Nutritional value
• Social interactions

Eating for Health
 Nutrition
• The science of the relationship between physiological
functions and essential elements of food
 Calorie
• Unit of measure that indicates the amount of energy we
obtain from a food
 Americans consume more calories per person
than any other group of people in the world
 Americans eat more fat (38%) than recommended
by nutritionists (no more than 30%)

Eating for Health
 Characteristics of a healthy diet
• Adequate
• Moderate
• Balanced
• Varied
• Nutrient dense

Figure 9.1
Trends in Caloric Intake and Food

Obtaining Essential Nutrients
 Digestive process
• Sequence of functions by which the body breaks down
larger food particles into smaller, more usable forms
• Our bodies cannot synthesize some essential nutrients
• Some essential nutrients obtained from food

Figure 9.2
The Digestive Process

Water
 Dehydration – abnormal depletion of body fluids
 The major component of blood
 Necessary for
• Electrolyte and pH balance
• Transporting cells and O2
 Recommended amount – 8 glasses/day (64 ounces)
 50-60% of body is water
 Is bottled water better?

Protein
 Second most abundant substance in humans
 Key to every cell, antibodies, enzymes, and
hormones
 Transport oxygen and nutrients
 Role in developing/repairing bone, muscle, skin
 Vital for human life
• May need additional protein if fighting off infection,
recovering from surgery or blood loss, recovering from
burns

Proteins
 Amino acids
• Building blocks of protein
• 20 essential amino acids must be obtained from food
• 11 non-essential amino acids produced by the body
• Link together to form
• Complete protein – supplies all essential amino
acids
• Incomplete protein – may lack some amino acids,
but these can be easily obtained from different
sources
 Few Americans suffer from protein deficiencies
 Can you give examples of complete proteins?

Figure 9.3
Complementary Proteins

Figure 9.4
Calculating Your Protein RDA

Carbohydrates
 Best fuel – provide energy quickly and efficiently
 Two types
• Simple sugars
• Glucose (monosaccharide) – most common form
• Fructose (monosaccharide) – found in fruits and
berries
• Sucrose (disaccharide) – sources include granulated
sugar, milk and milk products
• Complex carbohydrates (polysaccharides)
• Starches – from flour, pasta, potatoes
• Stored in the body as glycogen
• Fiber

Carbohydrates
 Carbohydrates and athletes
• Sugar may be counterproductive
• CHO ingestion is necessary for competitive long events
• Carbohydrate loading
 Myth of sugar addiction
• Not related in long-term studies
• Moderation is the key

Carbohydrates and Weight Loss
 High protein/low carb diets
• Helped educate the public about nutrients, importance of
• Whole grains
• Fiber
• Low-sugar food choices

Fiber
 “Bulk” or “roughage”
 Indigestible portion of plants
 Insoluble
• Found in bran, whole-grain breads, most fruits and
vegetables
• Found to reduce risk for several forms of cancer
 Soluble
• Oat bran, dried beans, some fruits and vegetables
• Helps lower blood cholesterol levels
• Helps reduce risk for cardiovascular disease

Fiber
 Offers many health protections
• Colon and rectal cancer
• Breast cancer
• Constipation
• Diverticulosis
• Heart Disease
• Diabetes
• Obesity
 Most American eat far less than recommended
• Recommended is 20-30 grams and average is 12 grams

Fats
 Also called lipids
 Misunderstood but vital group of basic nutrients
• Maintain healthy skin
• Insulate body organs
• Maintain body temperature
• Promote healthy cell function
• Carry fat-soluble vitamins A, D, E, and K
• Are a concentrated form of energy

 Triglycerides make up 95% of total body fat
• Remaining 5% composed of substances like cholesterol
• Can accumulate on inner walls of arteries and
contribute to cardiovascular disease
• Ratio of cholesterol HDL/LDL helps determine risk
for heart disease
 Saturated vs. unsaturated fat
• Saturated mainly from animal sources, solid at room
temperature
• Unsaturated generally come from plants and usually
liquid at room temperature

Figure 9.5
Percentages of Saturated, Polyunsaturated, and
Monounsaturated Fats in Common Vegetable Oils

 Avoiding trans fatty acids
• Created by process of making liquid oil into a solid
• Increase LDL levels while lowering HDL levels
• Higher risk of coronary and heart disease, sudden
cardiac death
• Found in many margarines, baked goods and restaurant
deep-fried foods
• Food labels listing no trans fasts can still contain less
than 500 milligrams/serving

 Still need essential fatty acids
• Eat fatty fish
• Use healthier oils (including olive oil)
• Eat green leafy vegetables
• Walnuts, walnut oil
• Ground flaxseed

 Use moderation with fat intake
• Read food labels
• Use olive oil for cooking
• Avoid margarine with trans fatty acids
• Choose lean meat, fish, poultry
• Eat fewer cold cuts, less bacon, sausages, hot dogs,
organ meats
• Choose nonfat dairy products
• Use substitutes for higher-fat products
• Think of your food intake as an average, over a day or
two—if you have a heavy breakfast, eat a light dinner

Vitamins
 Potent, essential, organic compounds
• Promote growth, help maintain life and health
 Two types
• Fat soluble – absorb through intestinal tract with fat
• A, D, E, and K
• Water soluble – dissolve in water
• B-complex and C

Vitamins
 Few Americans suffer from vitamin deficiencies
• Often, vitamin supplements not necessary
• Too much of many vitamins can be harmful
 Why do you think so many people take vitamin
supplements?

Minerals
 Inorganic, indestructible elements that aid the
body
• Vitamins cannot be absorbed without minerals
 Macrominerals are needed in large amounts
• Sodium, calcium, phosphorus, magnesium, potassium,
sulfur, chloride
 Trace minerals are needed in small amounts
• Iron, zinc, manganese, copper, iodine
• Excesses or deficiencies of trace minerals can cause
serious problems

Determining Nutritional Needs
 Recommended Dietary Allowances (RDAs)
 Adequate Intake
 Daily Values
 Recommended Daily Intakes (DRIs)
 Daily Reference Values (DRV)
 Reading food labels can help determine needs

Figure 9.6
Reading a Food Label

 Discussion Questions
• Discuss whether you think manufacturers are
intentionally misleading consumers regarding serving
size listings on their products. Why or why not?
• What kinds of standards for food labeling would you
recommend to manufacturers?
ABC News: Nutrition
Play
Video
| Nutrition

The New MyPyramid Food Guide
 Replaced the food guide pyramid to account for
varied nutritional needs throughout the U.S.
population
 Emphasizes
• Personalization
• www.mypyramid.gov
• Gradual improvement
• Physical activity
• Variety
• Moderation
• Proportionality

Figure 9.7
The MyPyramid Plan

Figure 9.8
Serving Size Card

Figure 9.9
Nutritional Needs for Different Groups

Vegetarianism: Eating for Health
 MyPyramid Plan adaptable for a vegetarian diet
 Types of vegetarian diets
• Vegan
• Lacto-vegetarian
• Ovo-vegetarian
• Lacto-ovo-vegetarian
• Pesco-vegetarian
• Semivegetarian

Vegetarianism: Eating for Health
 Reasons why 5-15% of the population are
vegetarians
• Aesthetic
• Animal rights
• Economic
• Personal
• Health
• Cultural
• Religious

The Medicinal Value of Food
 Compelling evidence that diet may be as effective
as drugs
• Functional Foods
• Antioxidants
• Carotenoids

The Medicinal Value of Food
 Folate
• Form of vitamin B
• Folate fortification 1998
• Neural tube defects
• Heart disease
 Probiotics
• Found in fermented milk products

Supplements
 Dietary supplements
• Products taken by mouth to supplement existing diets
• Includes vitamins, minerals, herbs
• FDA does not evaluate supplements prior to their
marketing; companies responsible for own
monitoring
• If in doubt about supplements, simply eat from the
major food groups
• A multivitamin added to a balanced diet will
generally do more good than harm

Gender and Nutrition
 Men and women have different needs
• Women have cyclical changes
• Men have more lean tissue (burn more)

Changing the “Meat-and-Potatoes” Diet
 Reasons to change
• Heavy red meat eaters are five times more likely to get
colon cancer, and twice as likely to develop prostate
cancer
• Fruits and vegetables reduce stroke risk as well as risk
for oral, bladder, and pancreatic cancers
• Cancer of the esophagus is one of the fastest rising
malignancies in the U.S., among white men in particular

Improved Eating for the College Student
 Variety of challenges for healthy eating
 Eating breakfast and lunch vital for keeping
energy up throughout the day
• Make lunch and bring it with you, including healthy
snacks
• Will keep you from buying less healthy food on the
run
• Limit sugar-heavy beverages and fried products

Improved Eating for the College Student
 Nutritional eating on a budget can be done
• Buy vegetables locally and in season
• Use coupons or shop at discount or bulk food stores
• Your city or county health department may have
suggestions if you don’t have the funds to eat properly

Food Safety: A Growing Concern
 Food-borne illness
• Affects millions of people each year
• Responsible for 5,000 deaths a year
• Signs
• Cramping
• Nausea
• Vomiting
• Diarrhea

 Key factors why food-borne illness has increased
• Globalization of food supply
• Inadvertent introduction of pathogens to new geographic
regions
• Exposure to unfamiliar food-borne hazards
• Changes in microbial populations
• Increases susceptibility of varying populations
• Insufficient education about food safety

 Practice responsible food handling at home
• Keep hot foods hot, and cold foods cold
• Freeze or eat fish, poultry, or meats within 1 or 2 days
• Eat leftovers within 3 days
• Wash hands, cutting boards, counters, and knives well
• Use a meat thermometer
• Never thaw foods at room temperature

Food Irradiation: How Safe Is It?
• Approved by USDA in
February 2000
• Use gamma irradiation from
radioactive cobalt, cesium, or
other X-ray sources
• Breaks chemical bonds in the
DNA of bacteria
• Rays essentially pass through
the food
• Lengthens product shelf-life,
prevents spread of
microorganisms
• Reduces need for toxic
chemicals currently used
• Marked with the “radura”
logo

Food Additives
 Reduce food-borne illness
 Enhance nutrients
 Intentional food additives
• Antimicrobial agents: salt, sugar, nitrates
• Antioxidants: preserve color and flavor
• Artificial color, nutrient additives, flavor enhancers
• Sulfites
• Dioxins: found in coffee filters, milk containers, and
frozen foods
• Methylene chloride: found in decaffeinated coffee
• Hormones: bovine growth hormone found in animals

Food Allergies and Intolerances
 Food allergies
• Abnormal response to a food triggered by the immune
system
• Found in 5% of children and 2% of adults
• Occurs when the body treats a food, usually protein, as
an invader
• Initial signs include rapid breathing or wheezing, hives,
rash, eczema, or runny nose
• More dramatic symptoms: facial swelling or respiratory
problems (anaphylactic reaction)
• Anaphylactic reaction requires a shot of epinephrine, a
hormone that stimulates the heart
• Can be mistaken for food intolerance or reactions to
food additives

Food Allergies and Intolerances
 Food intolerances
• Less dramatic reaction than food allergies
• Not the result of immune system response
• Generally shows as gastric upset
• Lactose intolerance common, also happens in response
to food additives (MSG, sulfites, gluten)
• May have psychological triggers

Organic
 Food developed, grown,
or raised without use of
synthetic pesticides,
chemicals, or hormones
 Becoming much more
common

Organic
 Foods need to meet criteria set by USDA to be
certified organic
• Produced without hormones, antibiotics, herbicides,
insecticides, chemical fertilizers, genetic modification,
or germ-killing radiation
• Monitoring systems still under development
 Some concern that buying organic means buying
foods with less nutrients
• Buy close to home, get it in the refrigerator quickly
 Is buying organic really better?

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