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

Abstract

A 70-day metabolism and body analysis experiment was conducted to determine the effects of differences in the fat content of diets, with large increases in the intake of ten of the vitamins, as compared with earlier experiments, on the utilization of food energy and protein by growing albino rats. The subjects were three groups of twelve weanling males, each group containing one rat from each of the same twelve liters. A comparison was made between three diets containing 2, 10 and 30% of fat, respectively, these diets being so compounded and fed as to supply to each rat of a litter-three, 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. The statistically significant results were body gains of fat and energy, and decrease in the heat production, in the order of the increasing fat contents of the diets.