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Lecture 9c powerpoint - Faculty

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					ENERGY BALANCE


8 NOVEMBER 2010
Introduction to energy (nrg) balance

Constant spend and refuel- excess stored

Not all excess nrg in is stored-some extra nrg used
for maintaining extra body weight

Slow weight loss desirable –otherwise yo-yo effect
- diet and exercise is the key
Energy in

    a) Food composition

    b) Food intake
         Hunger

            Satiation

            Satiety

            Overiding hunger and satiety signals
Energy in
    Food composition

    Use of oxygen to break bonds- O2 as a
    nutrient concept

    Food composition
Energy in

Food intake
    Hunger
    Depends on food content of
    stomach in part
          —reduced amounts of food
               —smaller stomach—less demand;
          — larger amounts of food
               — larger stomach—larger demand

    Receptors in gi tract determine whether
              nutrient intake has been high or low
ENERGY INTAKE CONTINUED
   FOOD INTAKE CONTINUED

      Satiation and Satiety
       Satiation-When to stop eating
       Satiety- Do not start eating again

      Overiding hunger and satiety signals

           Boredom, stress, time of day,
           availability,
           sight, taste of food
Energy out
Components of energy expenditure

         Basal metabolism

         Physical activity

         Thermic effect of food-


         Adaptive thermogenesis
Energy out continued

50 % dietary Kcal to ATP and rest radiates as heat
ATP 50 % to work and 50 % to heat there only
25 % of kcal used

Basal metabolism
Just to keep the doors open and the heat and lights on
      -calculated as weight (lbs) x 10 cal/lb
ENERGY OUT CONTINUED
Physical activity
 body mass and activity (duration, frequency
 and intensity).

Thermic effect of food-
     nutrients-dat, metabolise and store

Adaptive thermogenesis

 Adaptation to stress (eg cold or exercise)
  - body needs extra energy to build tissues
GRAND TOTAL ENERGY OUT

2200 kcal/day for females

2900 kcal/day for males
Body weight, body composition and health
Body weight and its standards

     Weight within range recommended for
         height and sex

          10 % below std-underweight
          10-20 % over -overweight
          > 20% obese
Body weight, body composition and health
continued
Body weight and its standards continued

B) BMI
         Kg/m2

    underweight- <18.5
    correct 18.5-24.9
    overweight > 25- 29.9
    obese > 30
Body weight, body composition and health
continued
BODY FAT AND ITS DISTRIBUTION

 PERCENT BODY FAT- FOR GOOD HEALTH


                   MALES         FEMALES

    < 40 YEARS       22             32

    > 40 YEARS       25             35
Body weight, body composition and health
Continued
FAT DISTRIBUTION IS IMPORTANT TOO
    WAIST/HIP > 0.9 IN MEN AND > 0.8
    IN WOMEN -APPLE SHAPE-
    PROBLEMS WITH LDL AND
    ATHEROSCLEROSIS

     IN MEN AND WOMEN PEAR SHAPE
     REDUCES RISK OF ATHEROSCLEROSIS

Males –40 inch waist
Females-35 inch waist
Health risks associated with body weight and
body fat
  Health risks of underweight
           Preserve lean tissue against wasting
           Infertility
           Give birth to unhealthy infants

 Health risks of overweight
     Atherosclerosis(stroke)
     Diabetes-type 2 diabetes already discussed
     Cancer- weight and weight gain tied in here-
           not fully understood why- may be
          related to hormones
SUPPLEMENTS-ALL CLAIMS FALSE
MA HUANG-HERB CONTAINING EPHEDRINE
    ALLEGED TO INDUCE WEIGHT LOSS
CHROMIUM PICOLINATE- ALLEGED TO
    BURN FAT
SPIRULINA-POWDER FROM ALGAE –
    ALLEGED TO SUPPRESS APPETITE

GUAR GUM-ALLEGED TO SUPPRESS
APPETITE VIA ABSORBING WATER AND
BLOATING STOMACH
GYMNENA SYLVESTRE PLANT-CLAIMED TO
BLOCK SUGAR ABSORPTION

				
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