Are individual or group interventions more effective for long‐term weight loss in adults with obesity? A systematic review

Guidelines recommend individual and group interventions for weight loss, based on preference. Our 2009 systematic review compared long‐term effectiveness of individual or group approaches to the same intervention, but there are new randomized controlled trials (RCTs) of high‐quality data. We updated and expanded our previous systematic review. We searched Medline and Embase from 1966 to May 2021, and a clinical trial register from 1966 to 2017. Review Manager (5.4.1) was used to conduct meta‐analysis. Ten RCTs were included. The primary outcome, mean weight change at final follow‐up, was −1.33 kg (95% confidence interval CI: −2.04, −0.62; 10 trials, 2169 participants), favouring group interventions (p < .001). For the secondary outcomes, attainment of ≥5% body weight loss at final follow‐up, the risk ratio (RR) was 1.36 (95% CI 1.05, 1.77; three trials, 1520 participants), favouring group interventions (p = .02); attrition at final follow‐up was similar between group and individual arms of trials, RR 0.93 (95% CI 0.82, 1.07) (p = .31). Group interventions can be more effective than individual interventions for long‐term weight loss in adults with obesity. However, few studies were included in the clinically relevant, secondary outcome measures. Research on delivering group processes in weight management is needed.