Behavioural Interventions for Severe Obesity Before And/or After Bariatric Surgery: a Systematic Review and Meta-analysis

Background: Significant, sustained weight loss through conventional, non-surgical interventions is often unattainable for people with severe obesity (e.g. BMI ≥40 or ≥35 kg/m(2) with co-morbidities). Bariatric surgery is effective in treating severe obesity, but surgery alone without additional behaviour change management may not result in optimum long-term weight loss and maintenance. This systematic review and meta-analysis of randomised controlled trials evaluated the effectiveness of lifestyle interventions before and/or after bariatric surgery.

Methods: MEDLINE, Embase, Cochrane Central Register of Controlled Trials and clinical trials registers were searched for eligible studies. Key journals were handsearched. Last search date was on December 2014. Eligible interventions had the explicit aim of changing behaviour related to diet and/or physical activity, starting within 12 months of surgery, either pre- or post-operatively, and with at least 6 months' follow-up. The primary outcome was weight change; secondary outcomes included surgical complications, quality of life and changes in co-morbidities. Random effect meta-analyses were undertaken. Study quality was assessed with the Cochrane Collaboration's risk of bias tool.

Results: Eleven trials met the inclusion criteria. Behavioural interventions appear to improve weight loss at 12 months after bariatric surgery. Secondary outcome data were lacking and weight outcomes were reported inconsistently. Overall, the methodological quality of the identified trials was low.

Conclusions: The strength of evidence is limited by the relatively small number of trials identified and by their low methodological quality and short follow-up duration. Well-designed randomised controlled trials (RCTs) with long-term follow-up are required.