Do postoperative psychotherapeutic interventions and support groups influence weight loss following bariatric surgery? A systematic review and meta-analysis of randomized and nonrandomized trials.

Bariatric surgery is currently considered the most effective treatment of severe obesity, but considerable individual variations in weight loss results have been reported. We therefore conducted a systematic review and meta-analysis of studies investigating the effect of psychotherapeutic interventions and support groups on weight loss following bariatric surgery. A literature search was conducted in the databases PubMed and PsycINFO, identifying nine eligible studies reporting results of the effect of psychotherapeutic interventions and support groups on weight loss following bariatric surgery. The results revealed a statistically significant overall effect of both psychotherapeutic interventions and support groups on weight loss (pooled effect size correlation (ESr) = 0.18; p < 0.0001). When comparing the effect sizes of psychotherapeutic interventions and support groups, no difference was found (p = 0.51). Higher quality studies had smaller effect sizes (0.16) than studies with low quality scores (0.22), but the difference did not reach statistical significance (p = 0.26). Patients attending psychotherapeutic interventions or support groups in combination with bariatric surgery appeared to experience greater weight loss results than patients treated with bariatric surgery only. However, research in this area is characterized by a lack of methodological rigor, and it is recommended that future study designs include randomization and active attention control conditions.