Does variation in palatability affect the postprandial response in energy expenditure?

The impact of variation in palatability on diet- and sucrose-induced thermogenesis was studied in two experiments with 24 healthy young normal-weight subjects, 12 men and 12 women. In the first study, subjects received at random in duplicate either a normal liquid test meal (2,000 kJ, 12% protein, 33% fat, 55% carbohydrate), or an iso-energetic test meal made highly unpalatable with kinin. The difference in palatability did not have a significant impact on postprandial metabolism. In the second study subjects received at random either a palatable sucrose solution (900 kJ), an iso-energetic standard sucrose solution, or an iso-energetic unpalatable sucrose solution. Kinin and a citrus flavour were used to vary palatability. Postprandial energy expenditure over a period of 150 min was not significantly affected by differences in palatability. A separate control experiment to assess the effect of kinin on energy expenditure was carried out in eight subjects. Kinin had no significant effect on energy expenditure over a period of 120 min after ingestion.