Protein and the Thermic Effect of Food
The Thermic Effect of Food (TEF) is one of the three major components of daily energy expenditure, the other two components being a) Basal Metabolic Rate and b) the energy cost of activity.
The energy expenditure from TEF is related to the stimulation of obligatory energy-requiring processes associated with eating, digesting, absorbing, and storing food (as well as the facultative energy expenditure associated with hormone secretion, sodium-potassium ATPase pump activity, protein synthesis, and substrate recycling).
The TEF raise in metabolism spikes after meals, and gradually declines over ~10 hours (as determined by the return to Basal Metabolic Rate). The main determinant of TEF is the total energy content of the meal (total calories consumed), followed by the protein fraction of the meal.