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

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.