Meal size and frequency: effect on the thermic effect of food

The effects of meal size and frequency on thermic effect of food (TEF) were examined in seven healthy normal-weight young women. Each volunteer consumed in random order one of two identical meals [3138 kJ (750 kcal), 54.5% carbohydrate, 14.0% protein, 31.5% fat]. One meal was taken over 10 min [large meal (LM)] whereas the other was taken in six equal portions of 523 kJ (125 kcal) at 30-min intervals over a 3-h period [small meals (SM)]. Metabolic rate was measured for 1 h before and every 30 min after the meal started for 5 h. When expressed as either kJ/min (kcal/min) or kJ/5h (kcal/5h), TEF was significantly higher in the LM day than in the SM day (P less than 0.05). We conclude that the temporal pattern in which a mixed caloric load is eaten affects the thermogenic response and may be an important determinant of energy balance after a meal.