Slide 3 of 8
Daily energy expenditure is made up of the basal energy requirements that are needed for daily living as well as the amount of energy expended during physical activity. An additional component, known as the thermic effect of food comprises about 10% of a personís daily energy expenditure.
This calculation can provide a rough approximation of a personís energy expenditure. Basal metabolic rate (step 1) will depend largely on body size since larger people will require more energy at rest. The contribution from physical activity will vary by a personís activity status. This is expressed here as a multiple of a personís BMR since larger people will expend more calories for a given level of physical activity. The sum of these two effects provides an estimate of energy expenditure.