Dietary factor

The dietary factor is a numerical value which multiplies the resting metabolic rate as an indication of the energy expended in the metabolic reactions used to assimilate food sources. The food may be taken via the oral or intravenous route.

The dietary factor reflects diet-induced thermogenesis and can be divided into:

• obligatory thermogenesis: primarily, fat and protein synthesis in the liver using carbohydrate substrate
• adaptive thermogenesis: increased heat production in response to an increased calorie intake

Typically, in the post-operative patient on a balanced diet, the dietary factor is 1.15.