Lacking Skills to Improve Self-Control: Reward-Induced Loss of Inhibitory Control and Overeating in Restrained Eaters

Abstract

Given the vital role of inhibitory control in successful weight management, the aim of this study was to examine whether inhibitory control can be increased via incentives. Specifically, participants were randomly assigned to two conditions: In the reward condition, participants could earn a monetary bonus by performing well during an inhibition task. In the control condition, participants were not rewarded for their inhibition performance. Afterwards, we measured participants' craving and food intake during a taste test. Further, dietary restraint was included as a potential moderating factor: Restrained eaters chronically attempt to limit their food intake but are generally unsuccessful in their dieting attempts, due to decreased inhibitory control abilities. Results showed that, compared to the control condition, unrestrained eaters in the reward condition significantly improved in inhibitory control, experienced less craving for food, and also consumed less calories during the taste test. Restrained eaters, in contrast, were unable to improve inhibition performance, reported higher craving for food, and consumed more calories during the taste test relative to control. Restrained eaters therefore appear incapable of applying effective inhibition strategies and would probably benefit more from extensive training procedures that gradually increase inhibitory control in order to facilitate successful weight control.