INFLUENCE OF DIET COMPOSITION AND CALORIC INTAKE ON BODY WEIGHT OF WARM- AND COLD-ACCLIMATED RATS.

The well known reduction in growth rate of cold-acclimated rats has been shown to depend on a decreased gain in total body fat, without change in the gain in lean body weight. This has been observed in rats fed Lab Chow or a high-fat diet ad libitum. In those groups fed a high-carbohydrate diet ad libitum or calorie-restricted high-fat or high-carbohydrate diets, exposure to cold had no effect on the gain in neither total body weight nor lean body weight, which were already reduced by the diet; in those animals, the significant decrease in the gain in total body fat upon exposure to cold was compensated by a slight but unsignificant increase in the gain in lean body weight, so that differences in gain in total body weight were not significant.