Long term maintenance of weight loss with non-surgical interventions in obese adults: systematic review and meta-analyses of randomised controlled trials

OBJECTIVE To systematically review and describe currently available approaches to supporting maintenance of weight loss in obese adults and to assess the evidence for the effectiveness of these interventions. DESIGN Systematic review with meta-analysis. DATA SOURCES Medline, PsycINFO, Embase, and the Cochrane Central Register of Controlled Trials. STUDY SELECTION Studies were identified through to January 2014. Randomised trials of interventions to maintain weight loss provided to initially obese adults (aged ≥ 18) after weight loss of ≥ 5% body weight with long term (≥ 12 months) follow-up of weight change (main outcome) were included. STUDY APPRAISAL AND SYNTHESIS Potential studies were screened independently and in duplicate; study characteristics and outcomes were extracted. Meta-analyses were conducted to estimate the effects of interventions on weight loss maintenance with the inverse variance method and a random effects model. Results are presented as mean differences in weight change, with 95% confidence intervals. RESULTS 45 trials involving 7788 individuals were included. Behavioural interventions focusing on both food intake and physical activity resulted in an average difference of -1.56 kg (95% confidence interval -2.27 to -0.86 kg; 25 comparisons, 2949 participants) in weight regain compared with controls at 12 months. Orlistat combined with behavioural interventions resulted in a -1.80 kg (-2.54 to -1.06; eight comparisons, 1738 participants) difference compared with placebo at 12 months. All orlistat studies reported higher frequencies of adverse gastrointestinal events in the experimental compared with placebo control groups. A dose-response relation for orlistat treatment was found, with 120 mg doses three times a day leading to greater weight loss maintenance (-2.34 kg, -3.03 to -1.65) compared with 60 mg and 30 mg three times a day (-0.70 kg, 95% confidence interval -1.92 to 0.52), P=0.02. CONCLUSIONS Behavioural interventions that deal with both diet and physical activity show small but significant benefits on weight loss maintenance.