The effect of dietary protein levels on diet-induced thermogenesis in the rat.

Relative to rats fed a 15% protein-diet, 300-g rats fed a 5% protein-diet for 5 weeks consumed 19% more food but gained only 28% as much weight, showed twice the thermic response when fed, had twice as much subscapular brown adipose tissue with almost twice the specific GDP-binding activity. There was no difference between these groups in skeletal growth nor, unexpectedly, in the proportion of carcass fat.