ACTIVITY AND PATTERNS OF RATS FED A LOW-PROTEIN DIET AND THE EFFECTS OF SUBSEQUENT FOOD DEPRIVATION

Abstract

Rats previously fed a low-protein diet (5% casein) survive deprivation of food for a shorter period than do animals fed an adequate diet (20% casein) even though this be fed in isocaloric amounts. The present investigation examined effects of feeding a low-protein diet and of subsequent survival during food deprivation under various conditions: in activity and standard cages, in temperate (23 °C) and cold (5 °C) environments. During feeding, those animals provided with the low-protein diet did not exhibit a total running activity or activity pattern markedly different than those of pair-fed controls. The results revealed that the shorter survival in cold or temperate environment after a low-protein diet is not attributable to differences in (a) total running activity or activity pattern, (b) feeding pattern, or (c) previous caloric intake and weight change. It was also noted that rats in activity cages do not eat or gain as much as rats in standard cages.