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 sati ety and diet-induced thermogenesis, with different macronutrient compositio ns, 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 departme nt of Human Biology, Maastricht University. Subjects: Subjects were eight females, ages 23-33 y, BMI 23 +/- 3 kg/m(2), recruited from University staff and students. Interventions: Subjects were fed in energy balance, with protein/carbohydra te/fat: 29/61/10 and 9/30/61 percentage of energy, with fixed meal sizes an d 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 deviation s. 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 f at 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 differ ences 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 d ifferences in satiety over 24 h.