The effectiveness of social-support-based weight-loss interventions: a systematic review and meta-analysis

Objective: This systematic review and meta-analysis examined the effectiveness of social-support-based weight-loss interventions in adult populations with excess weight or obesity. Methods: We performed a systematic review of randomized controlled trials that reported on the effectiveness of weight-loss interventions which incorporated a social connectedness component. To this end, we conducted a rigorous database search of MEDLINE, Embase, PsycINFO, CINAHL, Cochrane, and PubMed for relevant articles. The quality of eligible trials was evaluated by the Cochrane Risk‐of‐Bias2 tool. Five meta‐analyses on intervention effectiveness in terms of weight loss were executed at 2–4-month assessment, 6-month assessment, end of intervention, and 3- and 6-month follow-up. Results: Twenty-four trials involving couples or peers targeting weight loss in 4 919 adults with BMI ≥ 25 met inclusion criteria. Meta-analyses detected no significant effect of social-support-based weight-loss interventions at either 2–4 month or 6-month assessment. There were, however, significant effects at end of intervention [95% CI 0.39, p = 0.04] and at 3-month [95% CI 0.63, p < 0.01] and 6-month [95% CI 0.34, p = 0.05] follow-up. Conclusions: There seem to be a significant effect at the end of intervention and 3- and 6-month follow-up. However, further high-quality studies are needed before drawing any clear conclusions. Trial registration: PROSPERO 2020 CRD42020173696.