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Healthful nutrition for fitness and sport

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					Healthful nutrition for
  fitness and sport

         Chapter 2
    Williams, 8th edition
             Introduction
A. Healthful nutrition is designed to
   optimize the life-sustaining properties
   of nutrients and other substances found
   in food
B. Modern developments in the food
   industry have improved food quality and
   safety
C. The provision of many high-fat, low-
   fiber foods appears to have increased
   the possibility of development of various
   chronic diseases
        Essential nutrients
Six classes:
  1. Carbohydrate
  2. Fat
  3. Protein
  4. Vitamins
  5. Minerals
  6. Water
Essential nutrients cannot be produced in
  adequate quantities in body and must be
  consumed in diet
    Nonessential nutrients
• May be formed in the body
• E.g. creatine phosphate is an
  important nutrient for energy
  production during exercise (involved
  with ATP re-synthesis) but it can be
  from several amino acids
• See table 2.2 on p. 40
 The Recommended Dietary
         Intakes
The RDA recommendations focus on
several factors
a. Amount that prevents a nutrient-
   deficiency disease
b. Amount that may reduce the risk of a
   health problem or chronic disease
c. Amount that may increase health
   risk
Dietary Reference Intake consists
    of four reference intakes

a.   Recommended Dietary Allowance
     (RDA)
b.   Adequate Intake (AI)
c.   Tolerable Upper Limit (UL)
d.   Estimated Average Requirement
     (EAR)
                 Terms
• Adequate Intake (AI): Recommended
  dietary intake comparable to the RDA, but
  based on less scientific evidence.
• Dietary Reference Intake (DRI):
  Standards for recommended dietary
  intakes, consisting of four values. See also
  AI, EAR, RDA and UL.
• Daily Value (DV): A term used in food
  labeling; the DV is based on a daily energy
  intake of 2,000 Calories and for the food
  labeled, presents the percentage of the
  RDI and the DRV recommended for healthy
  Americans.
        Terms, continued
• Estimated Average Requirement
  (EAR): Nutrient intake value
  estimated to meet the requirements
  of half the healthy individuals in a
  group.
• Tolerable upper limit (UL): The
  highest level of daily nutrient intake
  likely to pose no adverse health risks.
   Balanced diet and nutrient
            density
• The human body needs more than forty
  different nutrients to function properly
• Different conditions influence nutrient
  needs and the concept of a balanced diet
  a. Stage of the life cycle
  b. Sex
  c. Variations in life-style
  d. Health status
     Proper food selection
Six general categories of foods:
  a. Milk, yogurt and cheese
  b. Meat, poultry, fish, eggs, dry
     beans, and nuts
  c. Breads, cereals, rice, and pasta
  d. Vegetables
  e. Fruits
  f. Fats, oils, and sweets
 The 3 energy nutrients are
   called macronutrients
Macronutrient balance
recommendations:
a.   55-60% carbohydrates
b.   10-15% protein
c.   30% or less from fat
   “MyPyramid” Food Guide

                                 Represents
                                 the 2005
                                 Dietary
                                 Guidelines for
                                 Americans


See: http://www.mypyramid.gov/
Type in your age, sex, and activity level to get
  specific dietary recommendations
       MyPyramid, Steps to a
          Healthier You
• Emphasis:
  –   Variety
  –   Proportionality
  –   Moderation
  –   Activity
  –   Personalization
  –   Gradual improvement
    Food exchange system
• Guide that is similar to MyPyramid
• Foods in each exchange contain similar
  nutrient characteristics
  (1) Calories
  (2) Carbohydrates
  (3) Fat
  (4) Protein
• The system was developed for diabetics
  and for weight control
 Nutritional content of foods
    varies tremendously
• See:
 www.nal.usda.gov/fnic/foodcomp
• Provides detailed evaluation
  of many foods
        Key nutrient concept:
• Based on the fact that if eight key nutrients
  are adequate in your diet, you will probably
  receive an ample supply of all nutrients
     (1) Protein
     (2) Thiamin
     (3) Riboflavin
     (4) Niacin
     (5) Vitamin A
     (6) Vitamin C
     (7) Iron
     (8) Calcium
  Variety is key to meeting
        requirements
• See table 2.6 on p. 47 for RDA,
  food sources, and food
  group/exchange for each of the 8
  key nutrients
• Table 2.7 on p. 47 for sample
  menu
      Nutrient density
1. Foods with high nutrient density
   possesses a significant amount of
   a specific nutrient or nutrients per
   serving compared to its caloric
   content
2. Adopting a healthful diet will
   automatically increase nutrient
   density simply by decreasing the
   amount of dietary fat and sugar
Tips on improving “typical American diet”

• Reduce consumption of or modify type of
  dietary fat
• Increase the consumption of whole grain
  products
• Increase consumption of plant products
  (1) Beans and other legumes
  (2) Fruits
  (3) Vegetables

 See Center of Science in the Public Interest
 web page: http://www.cspinet.org/
2005 Dietary Guidelines for Americans

Highlights:
• Balance food with physical activity to
  achieve or maintain healthy body weight
• Eat nutritionally adequate diet consuming
  wide variety of nutrient-rich foods
• Choose diet moderate in total fat, but low
  in saturated and trans fats and cholesterol
• Choose plant-rich diet
• Choose beverage and foods to moderate
  intake of added sugars
          Highlights, continued
• Use less salt and sodium
• If you drink alcohol, do so in moderation
• Maintain adequate protein
• Include adequate calcium and iron
• Ensure food safety, preservation, and
  preparation
• Avoid excess food additives and supplements
• Enjoy food, eat what you like, balance it within
  overall healthy diet
See:
  http://www.healthierus.gov/dietaryguidelines/
           Vegetarianism
1. Vegans: no animal product and obtain most
nutrients from fruits, vegetables, breads,
cereals, legumes, nuts, and    seeds
2. Ovovegetarians include eggs in their diet
3. Lactovegetarians include foods in the milk
   group
4. Ovolactovegetarians eat both eggs and
   milk products
5. Semivegetarians do not eat red meat, but
   do eat fish and poultry
     Nutritional concerns with a
           vegetarian diet
• May be insufficient Calories for proper
  body maintenance
• Strict vegetarians may incur a vitamin B12
  deficiency because this vitamin is not
  found in plant foods
• Vegans will need dietary supplements of
  vitamin D if not exposed to sunlight
• Mineral deficiencies of iron, calcium, and
  zinc may occur
• Major concern is to obtain adequate
  amounts of the right type of protein
       Protein, terms:
a. Complete proteins: have all
   essential amino acids (animal
   products)
b. Incomplete proteins: have some,
   but not all essential amino acids
   (plant products)
c. Complementary proteins:
   combination of plant foods that
   will make up complete protein when
   combined (grains and cereals
   complemented by legume )
Is a vegetarian diet healthier
  than an omnivorous diet?
Associated with reduced risk for numerous
chronic diseases and health problems
a. Total fat and saturated fat content is
   usually low
b. Plants do not contain cholesterol
c. Plant foods possess a high content of
   fiber and other nutrients associated
   with reduced levels of serum cholesterol
d. Supplies adequate nutrients and may be
   lower in Calories
 Plants are rich in antioxidant
     vitamins and minerals
 a.   Vitamin C
 b.   Beta carotene
 c.   Vitamin E
 d.   Selenium

* See table 2.11 on p. 58 for complete
  list of food sources
  Plants have phytochemicals that
   influence metabolic processes
 a.   Indoles
 b.   Isoflavones
 c.   Polyphenols
 d.   Phytoestrogens

* Collectively, antioxidant nutrients and
  phytochemicals are called
  “nutraceuticals”
   If interested in becoming
          vegetarian:
• Eat less meat
• Become a semivegetarian by
  substituting white meat for red
• Become an ovolactovegetarian by
  eating eggs and dairy products with
  vegetables
• Gradually phase out animal products
  as you learn to select foods for
  protein complementary and essential
  nutrients
  Will vegetarian diet affect
physical performance potential?
1. Studies: No differences found in
   aerobic or anaerobic capacities of
   vegetarian men or women
   compared with nonvegetarians
2. Important for vegetarian female
   endurance athletes to obtain
   adequate iron and calcium
3. Nothing magical about a vegetarian
   diet that will increase performance
  Consumer nutrition: Nutrition
        label information
Nutrition facts must be provided
 a.   List of ingredients
 b.   Serving size
 c.   Servings per container
 d.   Amount per serving
 e.   Total Calories, Calories from fat, Total
      fat, Saturated fat, Cholesterol,
      Sodium, Total carbohydrate,
      Dietary fiber, Sugars, Protein,
      Vitamin A, Vitamin C, Calcium, Iron
           Optional listings
•   Calories from saturated fat
•   Polyunsaturated fat, monounsaturated fat
•   Potassium
•   Soluble fiber, Insoluble fiber
•   Sugar alcohols, Other carbohydrates
•   Vitamins D, E, and K, All B vitamins
•   Phosphorus, Magnesium, Molybdenum,
•   Iodine, Potassium, Chloride
  Using food label information to
       select healthier diet:
• Daily Value (DV) represents percent age
  contribution one serving of the food makes
  to daily diet for that nutrient based on
  current recommendations
  (1) DV based on a 2,000 Calorie diet
      (a) Total fat: maximum of 30 %
            of Calories, or < 65 grams
      (b) Saturated fat: maximum of 10%
            of Calories, or < 20 grams
      (c) CHO: minimum of 60 % of
            Calories, or > 300 grams
 DV based on 2000 cal diet,
        continued:
(d)    Protein: based on 10% of
       Calories
(e)    Fiber: based on 12.5 grams of
       fiber per 1,000 Calories
(f)    Cholesterol: < 300 mg
(g)    Sodium: < 2,400 mg

* See figure 2.10 on p. 62
Health claims allowed on food
            labels
a. Calcium and osteoporosis: 20 % or more
   of DV for calcium
b. Fat and cancer: must meet definition
   for low fat
c. Saturated fat, cholesterol, and
   coronary heart disease: must meet
   definition for low saturated fat, low
   cholesterol, and low fat
d. Fiber containing grains, fruits,
   vegetables, and cancer: must meet the
   definition for low fat and be, without
   fortification, a good fiber source
Health claims allowed on food
      labels, continued
e. Fruits, vegetables, and grain products
   that contain fiber and risk of coronary
   heart disease: must meet definition for
   low saturated fat, low cholesterol, low
   fat, and contain 0.6 g soluble fiber
f. Sodium and hypertension: must meet
   the description for low sodium
g. Fruits and vegetables and cancer: must
   meet definition for low fat and be a
   good source of either fiber, vitamin A,
   or Vitamin C
Health claims allowed on food
      labels, continued
h. Oats and heart disease: must be low fat
   and contain at least 0.75 grams of
   soluble fiber
i. Folic acid and neural tube defects: must
   be a good source of folic acid
j. Sugarless gum and cavities: must meet
   definition of sugar-free
k. Soy protein and risk of coronary
   heart disease: must contain at least
   6.25 grams of soy protein per serving
     Health claims allowed on food
           labels, continued
l.     Plant sterol and stanol esters and
       reduced risk of heart disease: Must be
       consumed in 2 servings at different
       times of day
m.     Whole grain and heart disease: Must be
       low in total fat, saturated fat, and
       cholesterol
n.     Potassium and high blood pressure or
       stroke: Food must be a good source of
       potassium, at least 350 mg, and must be
       low sodium
         Functional foods
• The Dietary Supplement Health and
  Education Act (DSHEA) allows
  structure and function claims on
  products
• Functional foods provide health
  benefits beyond basic nutrition
  – a.   Fortification with nutrients
  – b.   Fortification with nutraceuticals
       Functional foods:
• Need to be evaluated with four
  questions
  a. Does it work?
  b. How much does it contain?
  c. Is it safe?
  d. Is it healthy ?
   Food quality and safety
• Safety and effectiveness of food
  biotechnology
 a. Genetically engineered food meets
    stringent safety standards and do not
    differ from conventional foods in
    quality or safety
 b. Benefits of biotechnology outweigh
    risks (regulated by FDA, USDA, EPA)
 c. Significant differences in nutrient
    content from conventional counterpart
    or introduction of a known allergen must
    be identified by special label
Pesticides and health concerns
a. The prudent individual should avoid
   direct contact with pesticides
b. With produce, analyzed data shows
   that synthetic and naturally-occurring
   pesticides are consumed at such low
   levels that they pose little threat to
   health
c. Meat products may contain higher
   amounts of pesticides
d. Fish from contaminated waters may
   contain high levels of pesticides
Ways to reduce pesticide content in
          foods we eat
• Avoid direct skin or breathing exposure to
  pesticides
• Food preparation:
  – (a) Wash produce
  – (b) Peel fruits and vegetables
• Eat less animal fat and seafood from
  contaminated waters
• Buy fruits and vegetables locally and in
  season
• Eat wide variety of foods
• Buy certified organic foods
Food processing: food quality
        and safety
A. Major purpose of food processing
   is to prevent waste through
   deterioration or spoilage
B. Food processing results in the loss
   of some nutrients, but not major
   losses
C. Food companies may enrich or
   fortify certain products before
   marketing
 Food processing, continued

Major problem with food processing
is the excessive use of highly refined
products
(1)     Sugar
(2)     Oils
(3)     Un-enriched white flour
(4)     Salt
What about food poisoning?
(1) Caused by consuming bacteria
    contaminated food
(2) Irradiation may eliminate or
    reduce bacteria and reduce the
    need for many food preservatives
(3) Care in preparation of food at
    home can prevent the spread of
    bacteria
What about food additives?
  (1)    Add flavor
  (2)    Enhance color
  (3)    Improve texture
  (4)    Preserve the food
• Additives must be Generally
  Recognized as Safe (GRAS) to earn
  FDA approval
     Food intolerance vs.
        food allergy
A. Food intolerance
   (1) Does not involve immune system
   (2) Body lacks the appropriate
        enzyme to digest a portion of the
        food (e.g. lactase for lactose)
B. Food allergy
  (1)   Adverse immune response to a
        food
  (2)   Allergens may be found in food or
        food additives (e.g. shellfish)
   Nutrition recommendations for
    better physical performance
Prior to competition, pre-competition meal:
  a. Allows for stomach to be
      relatively empty at the start of
      competition
  b. Prevents or minimizes GI distress
  c. Helps avoid hunger,
      lightheadedness, or fatigue
  d. Provides for adequate fuel,
      primarily CHO, in blood and muscles
  e. Should provide for adequate
      amounts of body water
      General guidelines
a. Solid meals should be eaten about 3-4
   hours prior to competition
b. Should be high in CHO and low in fat
   and protein providing easy digestibility
c. Adequate fluid intake should be assured
   prior to an event
   (1) Diuretics should be avoided
   (2) Large amounts of protein should
         be avoided
d. The meal should consist of foods that
   are high in complex CHO
e. Foods should be agreeable to you
General recommendations
(1) Morning events: eat a meal similar to
    breakfast
(2) Early to mid-afternoon events: eat a
    substantial breakfast and a
    precompetition meal for lunch
(3) Late afternoon events: eat breakfast,
    lunch, and snacks
(4) Evening events: eat breakfast, lunch,
    and a precompetition meal for dinner
           Liquid meals
1. Advantages over solid meals for
   precompetition nutrition
   a.    Well balanced in nutritional value
   b.    High-carbohydrate content
   c.    No bulk
   d.    Easily digested and assimilated
   e.    More practical and economical
2. May be taken closer to competition, two
   to three hours before
3. Should be used primarily as substitute
   for precompetition nutrition, not on a
   long-term basis
         Sports bars
1. Ingredients will vary
   a. Good source of CHO
   b. Most contain some protein
   c. Most contain some fat
2. They do not possess any magical
   qualities to enhance performance
3. They are convenient
What to eat during and after
       competition:
• During: Carbohydrate and water may
  be needed. In rare instances, a
  hypotonic salt solution may be
  recommended
• After activity of a prolonged nature,
  stress complex CHO foods
• For those who must compete several
  times daily and eat between
  competitions, the principles relative
  to pregame meals may be best
 Tips: Healthy eating while
         traveling
• Even if fast-food restaurants are
  all that is available, can make
  some healthier selections
• See list on p. 75
• See table 2.15 on p. 76

				
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