Intermittent feeding alters sensitivity to changes in reward value

Abstract

The influence of binge-like feeding schedules on subsequent food-related behavior is not well understood. We investigated the effect of repeated cycles of restriction and refeeding on two food-related behaviors; goal-directed responding for a palatable food reward and sensory-specific satiety. Hungry rats were trained to perform two instrumental actions for two distinct food outcomes and were then subjected to repeated cycles of restricted and unrestricted access to their maintenance chow for 30-days or were maintained on food restriction. Goal-directed control was then assessed using specific satiety-induced outcome devaluation. Rats were given 1 h access to one of theoutcomes and were then immediately given a choice between the two actions. Rats maintained on restriction responded more for the valued than the devalued reward but rats with a history of restriction and refeeding failed to show this effect. Importantly, all rats showed sensory-specific satiety when offered a choice between the two foods, indicating that pre-feeding selectively reduced the value of the pre-fed food. By contrast, sensory-specific satiety was not observed in rats with a history of intermittent feeding when the foods were offered sequentially. These results indicate that, similar to calorically dense diets, intermittent feeding patterns can impair the performance of goal-directed actions as well as the ability to reject a pre-fed food when it is offered alone.

Keywords: Goal-directed action; Habit; Instrumental conditioning; Outcome devaluation; Rat; Sensory-specific satiety.