Effects of stress on dietary preference and intake are dependent on access and stress sensitivity

Recent studies support a link between stress and the increased consumption of palatable foods. However, there has been a noted lack of genetic models to examine predisposing factors of overweight, obesity, and binge eating, particularly the role that stress sensitivity might play in the development of these conditions. We have examined the effects of chronic stress exposure on macronutrient choice preferences in a genetic mouse model of stress sensitivity (corticotropin-releasing factor receptor-2 deficient mice). Mice were provided with high fat, high protein, and high carbohydrate diets during exposure to chronic variable stress (CVS). Mice given free access to these diets during CVS selected a greater proportion of their calories in the form of the high fat diet compared to non-stressed mice. Apparent genotypic differences in high protein and high carbohydrate preferences were also diminished during the stress exposure. Stress-sensitive mice showed reduced weight gain and caloric efficiency during CVS, indicating a role for this phenotype in energy balance. When the preferred high fat diet was provided under limited access, stress-sensitive mice showed an increase in high fat consumption during CVS that was not observed in wild type mice, indicating a potential role for stress sensitivity in stress-induced bingeing. These studies support an involvement of stress pathways in macronutrient selection where stress selectively elevates the intake of a preferred high fat diet. Based on the alterations in caloric efficiency, increases in stress sensitivity may further predispose an organism toward altered energy balance in times of stress. (c) 2007 Elsevier Inc. All rights reserved.