CH 11: Achieving and Maintaining a Healthy Body Weight

  1. Healthful Body Weight?
    • a weight that is appropriate for your age and physical development
    • a weight that you can achieve and sustain without severely curtailing your food intake or constantly dieting
  2. BMI - Body Mass Index
    • commonly used index representing the ration of a person's body weight to the square of his/her height
    • Underweight - too little body fat
    • Overweight - having a moderate amount of excess body fat, not obese
    • Obese - having an excess body fat that adversely affects health
    • Morbid obesity - very high risk for serious health consequences
    • Limitations? - cannot consider fat mass to fat free mass, cannot identify where fat is stored
  3. Methods to Measure Body Composition
    • Hydrostatic Weighting - Most accurate, 2-3% margin of error
    • Skinfolds - 3-4% margin of error
    • Bioelectrical Impedance Analysis - 3-4% low level of electrical current, water good conductor of electricity - lean mass is made mostly of water
    • DEXA - dual-energy x-ray absorptiometry, low level of x-ray differentiates among bone tissue,lean tissue, fat tissue, lay for 30 min, 2-4% margin of error
    • Bod Pod - air displacement, door closed with person inside wearing a swimsuit - air displaced is measured 2-3% margin of error
  4. Body types
    • Android - apple-shaped
    • Gynoid - pear-shaped
  5. Apple-shaped
    upper body obesity, significantly causes in crease in risk for chronic disease, believed to cause problems in metabolism of fats and carbohydrates
  6. Pear-shaped
    lower body obesity, little increase for chronic disease
  7. Measurements
  8. Energy Intake and Expenditure
    • Energy Intake and Expenditure are out of balance
    • Energy expenditure = the amount of energy we expend at rest and during physical activity
    • Balanced is when we consume the same amount as we burn
    • Lose weight? - burn more than take in
    • Gain weight? - take in more than what you burn
    • Excess intake of 3,500 kcal = gain in lb
    • Without exercise, weight gain will likely be fat
  9. Energy Expenditure includes more than Physical Activity
    • Basal Metabolic Rate
    • Thermic Effect of Food
    • Energy cost of physical activity
  10. Basal Metabolic Rate
    • Energy expenditure at REST (respiration, circulation, body temperature, synthesis of new cells and tissue, secretion of hormones, nervous system activity)
    • Majority of our energy output 60-75% of our energy goes to fuel the basic activities of staying alive
  11. Factors that increased BMR
    • higher lean body mass
    • greater height
    • younger age
    • elevated levels of thyroid hormone
    • stress, fever, illness
    • male gender
    • pregnancy
    • drug-stimulants
  12. Factors that decrease BMR
    • lower lean body mass
    • lower height
    • older age
    • depressed levels of thyroid hormone
    • starvation or fasting
    • female gender
  13. Thermic Effect of Food
    • Energy expended to process the food we eat
    • Energy used to digest, absorb transport, metabolize, and store the nutrients we need
    • 5-10% of the energy content of the meal, relatively small amount
    • Fat = little energy to digest, transport, store
    • Proteins / Carbohydrates = more energy to process
  14. Energy Cost of Physical Activity
    • Represents 15-35% of our total energy each day
    • Energy expended to movement or movement or work above basal levels
    • Low intensity and high intensity activities
    • Be active for longer periods
Card Set
CH 11: Achieving and Maintaining a Healthy Body Weight
nutrition, healthy body weight