Ch 8: Energy Balance, Body Comp Flashcards
energy balance
when energy in = energy out
- weight stays consistent when this happens
how many kcal are in 1 pound of fat?
1 kg of fat?
1 lb of fat = 3500kcal
1 kg of fat = 7700kcal
rapid changes in weight are due to
water loss
excess energy stored as
fat when energy in > energy out (ie positive energy balance)
basal metabolism
accounts for 2/3 of out energy expenditure
- resting metabolic rate is the energy expended to support our body at rest
factors affecting basal metabolic rate
- having a higher VO2 max increases your BMR
- body composition: more lean tissue = higher BMR
- gender: males usually have higher BMR
Body Mass Index
- shows no info about body comp (problematic when muscle weighs more than fat), works generally for healthy people though <18.5 underweight 18.5-24.9 healthy 25-29.9 overweight 30+ obese
how to calculate BMI
= mass in kg / (height in metres)^2
body fat distribution
can be visceral or subcutaneous
- simply where you store excess fat
- dependent on gender,
- men should be under 20%
- women should be under 30% (higher bc estrogen is stored as fat)
subcutaneous fat
stored under the skin, usually lower body
- less of a problem health wise
visceral fat
- stored around the middle: central obesity
- waist circumference is an indicator of visceral fat and predicts disease risk much better than BMI
waist circumference measurements to be at risk for disease:
women: > 35 in
men: > 40 in
ways of measuring body fat distribution
skinfold measures hydrodensitometry bioelectrical impedance air displacement plethysmography DEXA waist circumference
health risks assoc w body weight and body fat
- more risks assoc w being sedentary and slim than fit and fat
- cardiovascular disease
- diabetes
- cancer
- inflammation and metabolic syndrome
female athlete triad
- disordered eating
- amenorrhea = lowered hormones due to low body fat
- osteoporosis
