Basal metabolic rate, nonshivering thermogenesis and cold tolerance in rat during undernutrition and subsequent nutritional rehabilitation.

Nutritional deprivation induced by increasing the litter size and subsequent dietary restriction results in rats having lower body weights and body lengths. Such undernourished rats have lower body temperatures as well as lower basal metabolic rate and nonshivering thermogenesis on a metabolic body weight basis; they also succumb on cold exposure to 5 degrees C. Nutritional rehabilitation by access to unlimited food reverses these changes to levels comparable to their control values.