Katherine Dews

Eating Behavior of Rats: How Macronutrient Self-Selection Relates to Emotionality

Faculty Mentor: Nancy Dess, Psychology Department

Major: Psychology

Funding: Ford Research Mentor's Endowment


Food preferences reflect and are affected by emotions. This study uses the overlap of ingestive systems and emotional systems to continue the elucidation of mental health mechanisms. Selectively bred rats are commonly used as models for individual differences among humans, and Occidental College rat lines are selectively bred based on a taste phenotype. These rat lines indicate that relative sensitivity to sweet tastes in comparison to bitter tastes indicates the rats’ proneness to stress, creating stress-prone low-saccharin consuming rats (LoS) and stress-resistant high-saccharin consuming rats (HiS). A prior study examining macronutrient self-selection by providing rats with simultaneous access to a fat, a protein, and a carbohydrate. HiS females consumed much more carbohydrate than fat, whereas their LoS counterparts consumed about equal amounts of carbohydrate and fat. The present study examined whether the difference between the two lines would be observed in replicate lines. Macronutrient self-selection was analyzed in female LoS and HiS rats from the first two generations of replicate lines. Rats had concurrent access to a fat, a protein, and a carb for three consecutive days. Results showed that the intake of carbohydrate was significantly greater than the other macronutrients, which was observed in the previous study. These early generations understandably do not yet show line differences. As selective pressure continues and future generations are tested, HiS rats’ continued preference for carbohydrate might emerge as reliable, which would support past conclusions concerning the relationship between food-related behavior and emotionality.

Watch my research presentation below.

Questions or comments? Contact me at: kdews@oxy.edu


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