Effect of chronic undernutrition on susceptibility to cold stress in young adult and aged rats.

Chronically undernourished laboratory rodents live as much as 50% longer than matched control animals fed ad libitum. In their natural habitats, however, most mammals, including humans, appear to have shorter life expectancies when chronically undernourished. The present research demonstrated that both brief and chronic undernutrition speeds rate of body temperature drop in rats exposed to cold air. Furthermore, chronic undernutrition also decreased the rate at which body temperature returned to normal after animals had been removed from the cold environment. These results suggest that while chronic undernutrition may slow the rate of physiological aging it also increases the organism's susceptibility to stressor stimuli.