Transcript Ch8 Powerpoint

Chapter 8 Lecture
Nutrition,
Health, and
Fitness
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Learning Objectives
• Define macro- and micronutrients
• Describe the macronutrients and the primary
functions of each
• Discuss the energy content of fats,
carbohydrates, and proteins in the body
• Describe the micronutrients and the primary
functions of each
• Discuss the value of water in the diet
• List the dietary guidelines for a well-balanced
diet
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Learning Objectives (cont.)
• Define the term calorie
• Describe the need for proteins, carbohydrates,
and vitamins for physically active individuals
• Discuss the benefits and detriments of irradiation
of foods
• Define a dietary supplement and discuss
governmental regulation for marketing such
supplements
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Nutrition
Study of food and how the body uses it to produce
energy and build and repair itself
Good nutrition includes
• Eating a diet supplying all of the essential
nutrients required to maintain a healthy body
• Taking in nutrients to prevent dietary
deficiencies
• Avoiding overconsumption of calories, sugars,
fats, and sodium
Complete Lab 8.1 to analyze your diet
Complete Lab 8.4 to assess nutritional habits
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Nutrients
Basic substances in food are required to maintain health.
There are two main categories
Macronutrients
• Needed in greater amounts
• Build/maintain body tissue and provide energy
• Carbohydrates
• Fats
• Proteins
Micronutrients
• Needed in smaller amounts
• Essential for many processes, including cell functions
• Vitamins
• Minerals
Water is an additional class of nutrient, critical for survival
and normal functioning
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Carbohydrates
• Main source of fuel for the brain
• Key energy source for muscular contraction
• 4 calories of energy per gram
• Includes whole grains, pasta, fruits, vegetables
Two types
• Simple carbohydrates (sugars)
– Glucose
– Glycogen
– Easier for the body to break down and use for energy
• Complex carbohydrates
– Starch (fuel source)
– Fiber (not a fuel source)
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Recommended vs. Typical Diet
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Fats
• Energy storage known as triglycerides
• Part of a larger class of substances called lipids
• 9 Kcals of energy per gram
Types of fatty acids
• Saturated (solid at room temperature/come from
animal sources)
• Monounsaturated
• Polyunsaturated
• Trans (found in baked and fried foods, and some
animal sources)
• Unsaturated (liquid at room temperature, come from
plant sources)
• Omega-3 (health benefits, found mainly in fish)
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Sources of Trans Fat in the Diet
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Proteins
• Build and repair body tissue
• Regulate metabolism/protect from disease
• 4 kcals per gram, usually not a major fuel source
• Basic structural units are amino acids
Complete Proteins
• Only in animal foods and soy products
• Contain all essential amino acids
Incomplete Proteins
• Present in vegetable sources
• Missing one or more of the essential amino acids
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Estimated Daily Protein Needs
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Vitamins and Minerals
Vitamins
• Help regulate growth and metabolism
• Water-soluble vitamins are not stored in the body (B and C)
• Fat-soluble vitamins are stored in the body (A, D, E, and K)
Minerals
• Chemical elements that help the body function
• Three key minerals: calcium, iron, sodium
– Osteoporosis: calcium deficiency disease
– Anemia: iron deficiency health problem
– Hypertension (high blood pressure): tied to too much sodium
In individuals who exercise, both vitamins and minerals help protect
against tissue damage
See Tables 8.2 and 8.3 Vitamin/Mineral Sources, Functions
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Water
• Comprises about 60–70% of your body
• Key nutrient for regulating body temperature,
digestion, absorption, blood formation, and
elimination
• Crucial for active people
• Losing as little as 5% body water causes marked
distress; more than 15% can be fatal
• Recommended to drink 8–10 cups per day
• Eating foods with high water content can help
you reach the daily minimum
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Daily Water Balance in the Body
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Guidelines for a Healthy Diet
• Eat more fruits, vegetables, and whole grains
• Balance what you eat with regular exercise
• Limit intake of calories, sugar, alcohol, fat, and
sodium
• Choose higher-fiber foods
• Take proper food safety precautions
• Use the Recommended Dietary Allowances
(RDAs), MyPlate, and food labels to plan healthy
meals
Complete Lab 8.2 to set goals for a healthy diet
Complete Lab 8.3 to plan a new diet
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MyPlate
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Using Nutrition Labels
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Special Dietary Considerations
Most people eating a balanced diet don't need supplements
Individuals with special needs benefit from vitamin and mineral
supplements
• Vegetarians: extra B12, D
• Pregnant women: folic acid
Others who may benefit
• People with chronic illnesses
• People on certain medications
• Athletes undergoing rigorous training
• Lactating woman
• People on prolonged low-calorie diets
Vegetarians
• Be careful to plan meals to meet body's need for
macro/micronutrients that may be missing due to not consuming
foods from animal sources
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Special Dietary Considerations (cont.)
Iron: Essential component of red blood cells
• Women menstruating, pregnant, or nursing need
adequate iron
– Too much has potential for toxicity
• Sources: legumes, fruits, whole-grain cereals, broccoli,
lean red meats, organ meats
Calcium: Essential for building bones and teeth
• Especially important for pregnant or nursing women
• May help prevent colon cancer
• Critical for children and teens
• Sources: low- and nonfat dairy foods, tuna fish, turnips,
mustard greens, broccoli
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How Does Nutrition Affect Physical Fitness?
• Carbohydrates are used for energy during
exercise
• Protein needs can be met with a healthy diet
• High vitamin intake WILL NOT improve
performance
• Antioxidants help prevent oxidative damage
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Carbohydrates and Exercise
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Do Supplements Enhance Health and
Performance?
Role of Supplements
• No scientific evidence currently validates the claim
that supplements improve health or exercise
performance
• Best approach is to eat a wide variety of foods and
avoid excessive supplements
Regulation of Supplements
• No FDA approval is required (supplements are not
tested)
• Manufacturers self-police the safety of supplements
with no oversight
• Manufacturers cannot make claims about
supplements concerning the treatment, prevention, or
cure of diseases
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Foodborne Illness
• Eating foods with some bacteria can make you sick Often causes
nausea, vomiting, and diarrhea within 12 hours to 5 days after
consumption
• Can be fatal in children or at-risk people
Safety Guidelines
• Select produce carefully
• Wash produce thoroughly
• Drink only pasteurized milk and juice
• Don't eat raw eggs or raw fish
• Keep perishables cold or frozen
• Cook all meats thoroughly
• Use separate cutting boards and utensils for meat and produce
• Wash and rinse dishes, utensils, and food preparation surfaces
thoroughly
• Wash your hands thoroughly before and after handling food
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Other Issues in Food Safety and Technology
Food additives are used by manufacturers to improve quality, taste
and/or color, and increase shelf life
• Common additives—sugar, salt, corn syrup, monosodium
glutamate (MSG), sulfites, nitrites
• Some people have greater sensitivity to additives and should
avoid or limit them
Organic foods are grown or raised without pesticides, hormones,
antibiotics or chemical fertilizers
• There is no research supporting the claim that organic foods are
nutritionally superior
Irradiation is used to kill microorganisms and prolong shelf life
• Data is limited regarding whether irradiation and bioengineered
foods are safe
• Irradiated foods use a label identifying them and attesting to their
safety
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Sample Program for Changing Daily Caloric
Intake
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Sample Program for Changing Daily Caloric
Intake (cont.)
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Sample Program for Changing Daily Caloric
Intake (cont.)
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Summary
• Nutrition is the study of food and its relationship
to health and disease
• Nutrients include macronutrients, micronutrients,
and water
• Vitamins and minerals play many important roles
in body regulation and functioning
• A healthy diet contains adequate amounts of
fruits, vegetables, whole grains, lean meats, and
dairy products, and limited quantities of sugar,
fat, sodium, and alcohol
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Summary (cont.)
• Calorie intake should be balanced against
calorie expenditure
• RDAs, MyPlate, and food labels can all help you
choose healthy foods in the proper proportions
• Most people who eat balanced diets do not need
supplements
• Foodborne illnesses can be largely prevented
through careful selection, preparation, storage,
and cleaning of foods, utensils, surfaces, and
hands
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