Objectives: To evaluate energy expenditure after three isoenergetic meals of different nutrient composition and to establish the relationship between the thermic effect of food (TEF), subsequent energy intake from a test meal and satiety sensations related to consumption. Design: The study employed a repeated measures design. Ten subjects received, in a randomized order, three meals of 2331 AE 36 kJ (557 AE 9 kcal). About 68% of energy from protein in the high protein meal (HP), 69% from carbohydrate in the high carbohydrate meal (HC) and 70% from fat in the high fat meal (HF). Setting: The experiments were performed at the University of Milan. Subjects: Ten normal body-weight healthy women. Methods: Energy expenditure was measured by indirect calorimetric measurements, using an open-circuit ventilated-hood system; intake was assessed 7 h later by weighing the food consumed from a test meal and satiety sensations were rated by means of a satiety rating questionnaire. Results: TEF was 261 AE 59, 92 AE 67 and 97 AE 71 kJ over 7 h after the HP, HC and HF meals, respectively. The HP meal was the most thermogenic (P`0.001) and it determined the highest sensation of fullness (P 0.002). There were no differences in the sensations and thermic effect between fat and carbohydrate meals. A signi®cant relationship linked TEF to fullness sensation (r 0.41, P 0.025). Energy intake from the test meal was comparable after HP, HC and HF meals. Conclusions: Our results suggest that TEF contributes to the satiating power of foods.