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.