Does a white bear help you eat less? The impact of the inhibitory spillover effect on eating behaviour

Overweight and obesity are global problems with negative physical, social, and psychological outcomes. Besides other factors, inhibitory control deficits contribute to weight gain and development of overweight. The inhibitory spillover effect (ISE) improves inhibitory control through transfer of inhibitory control capacity from one domain to an unrelated, second domain. For ISE to occur, one inhibitory control task is executed simultaneously with a second, non-control related task thereby increasing inhibitory control in this task.

In this preregistered study, we tested the ISE induced through thought suppression in contrast to a neutral task in participants with normal weight and overweight (N = 92). A simultaneously conducted bogus taste test served as outcome measure for food intake.

We found neither an interaction effect between group affiliation and condition nor an effect of group affiliation. However, contrary to our expectations, we found higher food intake in participants with active ISE compared to the neutral task.

This result might indicate rebound effects of applied thought suppression which led to the experience of loss of control and therefore undermined maintenance and function of the ISE. This main result was robust to all moderator variables. We elaborate further factors for the finding, theoretical implications, and future research directions.