Effectiveness of weight management interventions for adults delivered in primary care: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE To examine the effectiveness of behavioural weight management interventions for adults with obesity delivered in primary care. DESIGN Systematic review and meta-analysis of randomised controlled trials. ELIGIBILITY CRITERIA FOR SELECTION OF STUDIES Randomised controlled trials of behavioural weight management interventions for adults with a body mass index a25 delivered in primary care compared with no treatment, attention control, or minimal intervention and weight change at a12 months follow-up. DATA SOURCES Trials from a previous systematic review were extracted and the search completed using the Cochrane Central Register of Controlled Trials, Medline, PubMed, and PsychINFO from 1 January 2018 to 19 August 2021. DATA EXTRACTION AND SYNTHESIS Two reviewers independently identified eligible studies, extracted data, and assessed risk of bias using the Cochrane risk of bias tool. Meta-analyses were conducted with random effects models, and a pooled mean difference for both weight (kg) and waist circumference (cm) were calculated. MAIN OUTCOME MEASURES Primary outcome was weight change from baseline to 12 months. Secondary outcome was weight change from baseline to a24 months. Change in waist circumference was assessed at 12 months. RESULTS 34 trials were included: 14 were additional, from a previous review. 27 trials (n=8000) were included in the primary outcome of weight change at 12 month follow-up. The mean difference between the intervention and comparator groups at 12 months was-2.3 kg (95% confidence interval-3.0 to-1.6 kg, I2=88%, P(0.001), favouring the intervention group. At a24 months (13 trials, n=5011) the mean difference in weight change was-1.8 kg (-2.8 to-0.8 kg, I2=88%, P(0.001) favouring the intervention. The mean difference in waist circumference (18 trials, n=5288) was-2.5 cm (-3.2 to-1.8 cm, I2=69%, P(0.001) in favour of the intervention at 12 months. CONCLUSIONS Behavioural weight management interventions for adults with obesity delivered in primary care are effective for weight loss and could be offered to members of the public. SYSTEMATIC REVIEW REGISTRATION PROSPERO CRD42021275529.