Effect of diet textural characteristics on the temporal rhythms of feedingin rats

To examine whether the diurnal rhythms of protein-rich and carbohydrate-ric h diet ingestion can be altered by presenting the diets in different textur al forms, adult male Wistar rats were assigned to two dietary groups. One g roup received a two-way choice between high-protein powder and high-carbohy drate granular (HPP-HCG) diets. In the other group the textures were revers ed [high-protein granular and high-carbohydrate powder (HPG-HCP) diets]. Ra ts fed HPP-HCG diets selected significantly less protein (kcal) vs, rats fe d HPG-HCP diets, during the 24-h and 12-h dark phase and during the 4-h ear ly and late dark phases. Carbohydrate intakes of the two dietary groups wer e not significantly different. Total caloric intake for the HPG-HCP dietary ;group was significantly higher than that of the HPP-HCG dietary group duri ng the 24-h and 12-h dark phase. Body weight was significantly lower in rat s fed HPP-HCG diets. In conclusion, macronutrient-rich diets presented in d ifferent textural forms alter protein-rich diet ingestion and total energy intake. (C) 1999 Elsevier Science Inc.