Satiety related to 24 h diet-induced thermogenesis during high protein/carbohydrate vs high fat diets measured in a respiration chamber.

Objective: Assessment of a possible relationship between perception of satiety and diet-induced thermogenesis, with different macronutrient compositions, in a controlled situation over 24 h.

Design: Two diets with different macronutrient compositions were offered to all subjects in randomized order.

Setting: The study was executed in the respiration chambers at the department of Human Biology, Maastricht University.

Subjects: Subjects were eight females, ages 23-33 y, BMI 23+/-3 kg/m2, recruited from University staff and students.

Interventions: Subjects were fed in energy balance, with protein/carbohydrate/fat: 29/61/10 and 9/30/61 percentage of energy, with fixed meal sizes and meal intervals, and a fixed activity protocol, during 36 h experiments in a respiration chamber. The appetite profile was assessed by questionnaires during the day and during meals. Diet induced thermogenesis was determined as part of the energy expenditure.

Results: Energy balance was almost complete, with non-significant deviations. Diet-Induced-Thermogenesis (DIT) was 14.6+/-2.9%, on the high protein/carbohydrate diet, and 10.5+/-3.8% on the high fat diet (P < 0.01). With the high protein/high carbohydrate diet, satiety was higher during meals (P < 0.001; P < 0.05), as well as over 24 h (P < 0.001), than with the high fat diet. Within one diet, 24 h DIT and satiety were correlated (r = 0.6; P < 0.05). The difference in DIT between the diets correlated with the differences in satiety (r = 0.8; P < 0.01).

Conclusion: In lean women, satiety and DIT were synchronously higher with a high protein/high carbohydrate diet than with a high fat diet. Differences (due to the different macronutrient compositions) in DIT correlated with differences in satiety over 24 h.