Can smartphone-based response inhibition training elicit sustained changes in appetite, preference, and cravings for energy-dense foods? A free-living randomized controlled trial.

Background: Food-specific response inhibition training has been implemented as a strategy to modify food choices and reward-related eating behaviours, but short-term studies have produced equivocal findings.

Objective: To longitudinally assess the effect of a smartphone-based response inhibition intervention on food reward, hedonic eating drive, and cravings in a free-living setting.

Methods: 84 adults (M  = 30.49, SD  = 13.01, 52 female) with high responsivity to food cues or overweight/obesity were randomly assigned to a response inhibition training intervention (n = 45) or a control game (n = 39) at home during a training week, followed by a week with no training. Primary analyses compared groups on measures of explicit liking and implicit wanting for food of different energy densities, food cravings, and reward-related eating throughout this two-week period.

Results: A reduction was observed in explicit liking and implicit wanting for energy-dense foods from baseline to post-training independent of condition (ps < .001). These changes from baseline were sustained after a 1-week latency period, also independent of condition (ps < .001). These effects coincided with similar observations of hedonic eating drive, tonic cravings, and control over cravings during the observation period (ps < .01).

Conclusions: Although significant reductions in reward-related appetite were observed, free-living response inhibition training did not offer additional benefit over a control activity. Future intervention studies with observable food intake are needed to investigate which appetitive mechanisms most reliably predict eating behaviour over time.

Trial Registration: Retrospectively registered with ANZCTR [ACTRN12622001502729].