A cafeteria diet modifies the response to chronic variable stress in rats

Abstract

Stress is known to lead to metabolic and behavioral changes. The aim of this study was to investigate the effect of long‐term nutrient intake on the response to chronic variable stress (CVS). Adult Sprague‐Dawley rats were fed one of three diets for 6 weeks: high carbohydrate (HC), high fat (HF), or “Cafeteria” (CAF) (Standard HC and a choice of highly palatable cafeteria foods: chocolate, biscuits and peanut butter). After the first 3 weeks, half of the animals from each group were stressed daily using a CVS paradigm while the others (controls) were kept undisturbed. Rats were sacrificed at the end of the 6‐week period. Abdominal fat, serum lipids and corticosterone were measured. Results showed higher total cholesterol and LDL, and lower HDL associated with both chronic stress and the CAF diet; as well as an increase in body weight (P =0.03), food intake (P <0.001) and intra‐abdominal fat (P <0.001) in the CAF group compared to the other dietary groups. In addition, there was a significant interaction between stress and diet on serum corticosterone levels (P=0.012). More precisely, there was an increase in corticosterone levels of stressed rats compared to non‐stressed rats in the HC and HF groups but not in the CAF group. These results show that a highly palatable diet offering a choice of food items is associated with a reduction in the response to CVS and could validate a stressor‐induced preference for comfort food.