The Influence of Low Levels of Protein on Heat Production

Publisher Website
Google Scholar
Abstract
Study of the influence of various levels of protein in equicaloric diets on protein and energy metabolism has been extended in the present experiment to include very low levels of protein, 6 previous studies having covered the range of protein intake from 10 to 45%. Using a 70-day metabolism and body analysis technique with three groups of 12 litter-mate, growing albino rats, a comparison was made of three diets containing 6, 8 and 10% protein, respectively, these diets being so compounded and fed as to supply to each rat of a set of triplets the same gross energy, vitamins and minerals. The heat production was measured as a single value for 70 days by subtracting the energy of the excreta and body gain from the gross energy of the food. Gains in live weight, retention of nitrogen and fat in body tissue, increased digestibility of nitrogen, and decrease in heat production were in the order of increasing protein content of the diet. The principal demonstration of this entire series of studies is a decrease in heat production at a moderate rate as the protein in equicaloric rations increases from 6 to 45%.