Study Protocol: A Parallel-group, Randomized Controlled Trial of Enhanced Cue Exposure Therapy for Negative Emotional Eating

Abstract

Abstract Background: Negative emotional eating (NEE) refers to overeating in response to negative emotions. Cue exposure therapy (CET) has shown preliminary efficacy for treating disordered eating in pilot trials but its efficacy for treating specifically NEE has 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 not only food cues but also emotional cues and idiosyncratic contextual cues, (2) homework exposures that are conducted in the participant’s naturalistic environment to enhance the generalizability of the effects of exposures, and, (3) explicit instructions during exposures to violate the conditioned stimulus-unconditioned stimulus (CS-US) expectancies believed to be maintaining NEE. E-CET is hypothesized to promote greater reductions in NEE than an active control intervention, behavioral lifestyle intervention (BLI), and its efficacy will be mediated by the reduction in the believability of CS-US expectancies. Methods: A parallel-group, participant-blinded RCT will be conducted. One-hundred-and-thirty-eight participants who have recurring NEE will be randomly assigned to E-CET or BLI. Both E-CET and BLI will be delivered in six weekly 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 assessments, external eating, eating disorder symptoms, caloric consumption, body weight, mood, quality of life, and the believability in CS-US expectancies will be measured in the same period. Exploratory outcomes including the within-session changes in CS-US expectancies and the degree of habituation will be assessed in each exposure session, and treatment acceptability and satisfaction will be measured at posttreatment. Discussion: If shown to be efficacious, E-CET can be implemented to reduce NEE. Furthermore, this study will be the first experimental evaluation of the mediating effects of CS-US expectancy violation in the working of E-CET for NEE. This knowledge will inform developments of the theories on CET and NEE. Trial registration: ClinicalTrials.gov Identifier: NCT06012045, registered on 21 August, 2023.