Further Experiments on the Relation of Fat to Economy of Food Utilization

Abstract

An investigation of the possible influence of low protein intake on the superior energy utilization of high fat diets was conducted using 12 litter-mate pairs of weanling male albino rats subjected to a 70-day metabolism and body analysis procedure. A comparison was made between 2 diets containing 2% and 30% of fat, respectively, so prepared and fed as to supply to each rat of a litter-pair and therefore to each group of 12 the same quantities of energy, protein and vitamins. Determinations were made of gains in live weight, nitrogen, fat and energy, and of the heat production for 70 days as the energy of the food minus the energy of the excreta and of the body gain. Decreasing the protein intake from the former 22% level to 7% of the diet did not alter the previously reported superior energy utilization of high fat diets by the growing rat. In the present experiment an increased weight gain, increased body gains of fat and energy, and decreased heat production were associated with the high fat ration.