Effects of Lisdexamfetamine on Effort-Related and Consummatory Behaviors Supported by Foods with Varying Degrees of Palatability: Exploration of a Binge-Like Eating Model

Diets high in sugar or fat are associated with multiple health conditions, including binge eating disorder (BED). BED affects approximately 2% of the US adult population, and occurs more frequently in females. It is important to develop animal models of palatable food consumption, food seeking, and voluntary physical activity that may have relevance for BED. The d-amphetamine prodrug lisdexamfetamine (LDX) is used to treat BED. The present experiments studied the effect of LDX on food intake and effort-based choice tasks in female Wistar rats. In experiment one, three groups of rats received different food exposure conditions randomly spread over several weeks. In tests of food intake, LDX (0.1875-1.5 mg/kg IP) significantly reduced intake of both chocolate and chow. All rats were trained on a Progressive Ratio/chow feeding task, giving a choice between working for high carbohydrate chocolate flavored pellets by lever pressing vs. approaching/consuming a concurrently available lab chow. There was a significant overall dose-related suppressive effect of LDX on lever pressing but no group difference. LDX significantly decreased chow intake in experimental group, but not in the control group. In Experiment two, rats (n=8) were given brief access of a highly palatable food randomly over several weeks. All rats were trained on a novel T-Maze task giving a choice to eat or run on a running wheel. LDX (0.09375-1.5 mg/kg IP) significantly reduced intake of chocolate, and a trend towards reduced running wheel activity was seen. In conclusion, LDX affected food intake, food-reinforced operant behavior, and running wheel activity