Study protocol for a parallel-group, randomized controlled trial of enhanced cue exposure therapy for negative emotional eating

Background: Negative emotional eating (NEE) refers to overeating in response to negative emotions. The efficacy of cue exposure therapy (CET) for treating NEE not been evaluated in a full-scale randomized controlled trial (RCT). Moreover, previously tested CET did not fully utilize theory-informed intervention strategies. Hence, an enhanced version of CET (E-CET) is here developed and evaluated. E-CET will integrate theory-informed intervention strategies including (1) exposures that incorporate food cues, emotional cues, and idiosyncratic contextual cues, (2) homework exposures, and, (3) explicit instructions to violate the conditioned stimulus-unconditioned stimulus (CS-US) expectancies maintaining NEE. E-CET is hypothesized to promote greater reductions in NEE than an active control, behavioral lifestyle intervention (BLI), and its efficacy will be mediated by the reduction in the believability of CS-US expectancies. Methods: This is a parallel-group RCT. One-hundred-and-thirty-eight participants with recurring NEE will be randomly assigned to E-CET or BLI, and attend individual sessions. The primary outcome is the change in the emotional eating subscale score measured by the Dutch Eating Behavior Questionnaire at posttreatment, 3-month, and 12-month follow-up from baseline. Secondary and mechanistic outcomes include changes in NEE measured by ecological momentary sessments, caloric consumption, and the believability in CS-US expectancies. Discussion: If shown to be efficacious, E-CET can be implemented to reduce NEE. This study will be the first experimental evaluation of the mediating effects of CS expectancy violation in the working of E-CET for NEE to inform developments of the theories on CET and NEE.