Stress effects on rats chronically receiving a highly palatable diet are sex-specific

The stress response is known to lead to behavioral and metabolic changes. Exposure to chronic stress can promote the development of physiological and behavioral dysfunctions, including alterations in feeding behavior. The aim of this study was to verify whether chronic restraint stress alters the consumption of a highly palatable, highly caloric diet (chocolate), chronically offered to the animals. Male rats ate more chocolate than females, and they also exhibited a higher weight gain, abdominal fat deposition, and higher plasma levels of total cholesterol, LDL-cholesterol and glucose. The stress exposure decreased body weight, increased adrenal weight and decreased plasma insulin levels. Overall, female rats had lower plasma insulin levels and chocolate consumption prevented the increased adrenal gland weight after exposure to chronic stress, suggesting a reduction of stress effects induced by palatable food consumption. Taken together, these results suggest a peculiar metabolic pattern, related to energy store and expenditure, in stressed animals receiving a palatable diet. Since these effects were sex-specific, we may also propose that females and males subjected to restraint stress and chocolate consumption are differentially affected.