week 4: energy & energy balance Flashcards
what is energy balance?
balance in body between amounts of energy consumed (energy intake) & energy expanded (energy output)
what is positive EB?
increase in body energy stored & weight gain
what is negative EB?
depletion of body energy stored & weight loss
what is energy intake represented by?
no. of calories eaten each day
what is EI affected by?
appetite
what is appetite?
sensation of hunger, satiation & satiety that prompts a person to eat/ not eat
what is the use of calorie (energy expenditure) for?
- to maintain basic body function
- to power physical activity
- to process consumed food
what is basal metabolism?
the energy needed to accomplish its most basic life-sustaining functions
under what condition must it be to measure BMR?
- fasting for 12hrs
- sleeping for 8hrs upon wake without any physical activity/ emotional excitement
- in a comfortable setting
Describe Resting Metabolic Rate
- less restrictive than BMR
- individual x have to fast
- x have to get at least 8hrs of sleep in a controlled environment
- is conducted when individual is asleep
what does REE estimate?
the no. of calories a person burn during non-active period
what are the factors that increases BMR? (9 points)
- greater lean body mass
- larger body surface area
- thyroid hormones
- male gender
- pregnancy
- stress
- caffeine & tobacco use
- body temperature
- aspects of nervous system act.
what are the factors that decreases BMR (6 points)
- sleep
- fasting/starvation
- female gender
- malnutrition
- more body fat tissues
- aging
describe physical activity
- voluntary movement of skeletal muscles & support system
- extra energy is needed for activity
what are the factors that affect energy for PA?
- muscle mass
- body weight
- activity (intensity, duration, frequency)
what is energy output - TEF
an estimation of the energy required to process food
what makes up total energy expenditure (TEE)?
Required energy expenditure (REE), physical activity (PA), thermic effect of food (TEF)
what are the other factors that affect TEE?
adaptative thermogenesis (Physical conditioning, other stress, trauma, starvation, overfeeding, extreme cold)
what are the equations used to estimate energy requirement?
- Harris-benedict eqn
- MIfflin-st. Jear eqn
- formulae developed by food & nutrition board, USA
what is used to measure energy expenditure?
- direct calorimetry
- indirect calorimetry
describe direct calorimetry
- a measure of energy expenditure obtained by asessing heat loss
- measures the amount of heat that is released by the a person
what is the principle of direct calorimetry?
almost all the energy used by body will leave as heat
what is indirect calorimetry
a measurement of energy expenditure obtained by assesing oxygen consumption & carbon dioxide production
what is BMI used to indicate?
disease risk & death rates
what are the groups of people who are BMI exceptions?
children, adolscent, frail old people, pregnant & lactating women, highly muscular individuals
what makes up body weight?
fat mass & lean body mass
what are the methods to measure body fat?
- body FAT scales
- a skin fold caliper
- hand-hold electronic body fat meter
describe central obesity/ upper body fat
- characterised by large abdomen
- more common in men
- associated with weight-related health problems
describe lower body fat around hips and thighs
- less harmful than central obesity
- more common in women
what are the health risk associated with abnormal body weight (overweight)
hypertension, elevated blood cholestrol, some cancers, type 2 diabetes, stroke, heart disease
what are the health risk associated with abnormal body weight (underweight)
malnutrition, infertility, osteoporosis, low immunity
