Long term maintenance of weight loss with non-surgical interventions in obese adults: systematic review and meta-analyses of randomised controlled trials.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of 45 randomized controlled trials
PubMed 25134100 · doi:10.1136/bmj.g2646
What was done
A systematic review and random-effects meta-analysis of randomized controlled trials published up to January 2014 across Medline, PsycINFO, Embase, and Cochrane CENTRAL. The review included RCTs of non-surgical weight loss maintenance interventions in initially obese adults (aged ≥ 18) who had achieved ≥ 5% body weight loss, with weight change assessed at ≥ 12 months of follow-up. Study screening and data extraction were performed independently in duplicate.
What was found
Across 45 trials involving 7,788 individuals: - Behavioural interventions targeting both food intake and physical activity reduced weight regain by a mean difference of -1.56 kg (95% CI -2.27 to -0.86 kg; 25 comparisons, 2,949 participants) compared with controls at 12 months. - Orlistat plus behavioural interventions reduced weight regain by -1.80 kg (95% CI -2.54 to -1.06 kg; 8 comparisons, 1,738 participants) compared with placebo at 12 months, with higher rates of gastrointestinal adverse events reported in all orlistat trials. - Orlistat demonstrated a dose-response effect (P = 0.02), with 120 mg three times daily achieving -2.34 kg (95% CI -3.03 to -1.65 kg) versus -0.70 kg (95% CI -1.92 to 0.52 kg) for 30 mg or 60 mg three times daily.
Why it matters
This review establishes that while behavioural and pharmacological non-surgical strategies mitigate weight regain after substantial initial loss, the average maintained benefit at 12 months is modest (under 2.5 kg).
Limits
The absolute effect sizes are modest (1.5 to 2.3 kg difference at 1 year). The abstract does not provide data on outcomes beyond 12 months, long-term adherence, or clinical endpoints (such as cardiovascular or metabolic outcomes). Orlistat was associated with increased gastrointestinal side effects.