Conditioned stress-eating and stress non-eating in rats, and their preference for food sweetened with sucralose

Abstract

The current study examined different learning histories in relation to stress and food intake. In other words, stress-induced eating and non-eating could be due to different learned associations between a stressor and food. Seventeen male Sprague-Dawley rats were used to create a model of stress-eating and non-eating using operant conditioning. This model was then used to examine subjects’ food intake and preferences for food formulas sweetened with three different amounts of Splenda: 0%, 10%, and 60%. These formulas were first presented to the rats individually (onechoice test) while a high-frequency tone (the stressor) was present and absent. The second test (two-choice test) exposed the rats to 2/3 formulas at the same time while the stressor was present and absent. It was found that all rats, regardless of group assignment preferred chows containing no Splenda, as demonstrated by an increase in food intake. This did not change as a factor of stress. Additionally, conditioned stress-eaters increased their food overall food intake when the stressor was present, as compared to when it was absent. This was not observed for conditioned stress non-eaters. Limitations, implications, and future directions are discussed.