energy expenditure

Question 1

basal and resting metabolic rates

Answer 1

BMR (basal = sleeping)

• fasting 12 hours prior to test
• complete mental and physical relation
• often measured on waking; after sleep in hospital or metabolic ward

RMR

• less strict conditions
• 5-6 hours after a meal
• at rest following minimal activity

RMR ~10% higher than BMR

Question 2

RMR

Answer 2

accounts for 60-75% of total daily expenditure

~60% from organs

~25% from skeletal muscle

minimal rate of metabolism necessary to sustain life

represents the sum of cellular events essencial to life

predicting with:
body mass 
- 0.9-1 kcal/kg/hr
Body comp
- 21.6xFFM + 370kcal/day

Question 3

TEF
-thermic effect of feeding

aka:
DIT
MIT
TEM

Answer 3

accounts for ~10% of TDEE

MR elevates after meal ingestion

divided into:
Obligatory thermogenesis
- energy cost of digestion and processing of food to energy

Facultative thermogenesis
- activation of SNS to stimulate metabolism

Question 4

factors influencing TEF

Answer 4

macronutrient comp. (most thermogenic to least)

• protein
• carbs
• fat

fiber content (higher=faster)

age (>age = >TEF)

acute exercise
- after meal potentiates TEF

Alcohol

• increase in TEF offset by increase appetite
• increase RM, suppress fat oxidation

Question 5

AEE

activity energy expenditure

Answer 5

15-30% TDEE

structured PA (exercise) + non exercise activity thermogenesis (NEAT)

most variable component

Difficult component to quantify

Question 6

energy content in food

Answer 6

GE - gros energy
total chemical energy

DE - digestible energy
portion of GE actually absorbed into body

ME - metabolizable energy
amount of energy available for human metabolism

Question 7

Atwater

measuring ME from food

Answer 7

ME = GE - (Losses in poop and pee)

losses in poop

• 1% ingested carbs
• 5% ingested fat
• 8% ingested protein

losses in pee
- ~5.2kj/g protein

Question 8

atwater factors

Answer 8

protein 17kj/g
fat 37kj/g
carbs 17jk/g
alcohol 29kj/g

energy density in food measured by kj/g

Question 9

energy density of food

Answer 9

density of a hole food which is usually a mixture of macronutrients, water and other components