Abstract
BACKGROUND: Telephone-based Cognitive Behavioral Therapy (Tele-CBT) has shown to reduce disordered eating and psychological distress after metabolic and bariatric surgery (MBS). However, it is currently unknown how Tele-CBT impacts outcomes long term, and if differences in weight loss trajectories following Tele-CBT emerge with a long-term follow-up. This study aimed to identify whether Tele-CBT remains effective at 18 months post-intervention for improving psychological distress and maladaptive eating, and mitigating recurrent weight gain. METHODS: This large, multisite randomized control trial was conducted at three hospital-based MBS programs in Ontario, Canada. Participants (n = 306) were randomized 1:1 to receive either Tele-CBT or standard MBS care. The primary outcome was percentage of total weight loss (%TWL). Secondary outcomes included disordered eating (Binge Eating Scale, Emotional Eating Scale) and psychological distress (Patient Health Questionnaire-9, Generalized Anxiety Disorder-7). Linear mixed models assessed group-by-time interactions across five time points: baseline (1-year post-MBS), post-intervention, and 3-, 12-, and 18-month follow-ups. RESULTS: Tele-CBT resulted in significant post-intervention improvements in binge eating (MD = - 0.46, p < .001), emotional eating (MD = - 0.14, p = 0.01), anxiety (MD = - 0.40, p < .001), and depressive symptoms (MD = - 0.47, p < .001). These improvements were all sustained at 3 months post-intervention (p < .05) whereas only improvements for emotional eating were sustained at 12 months post-intervention (MD = - 0.15, p = 0.01). There were no significant differences in %TWL trajectories between the Tele-CBT and control groups. CONCLUSIONS: Tele-CBT provides psychological benefits, particularly in reducing emotional eating. Findings highlight the need for continued psychosocial support to sustain other psychological benefits and mitigate recurrent weight gain post-MBS and further research on optimizing intervention timing and duration. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03315247.