Factors influencing food intake of rats fed low-protein rations

Rats fed low-protein rations increased food intake, weight gain and gain in lean body mass when forced to expend energy by low environmental temperature or exercise (swimming). Rats fed low-protein rations with a higher proportion of fat in their weight gain had a greater food intake and gain in lean body mass. Therefore, gain in lean body mass was improved not only by stimulating energy loss by cold environment or exercise but by an innate ability to deposit more fat in the weight gain, because of an increased food intake, and hence protein intake.