Comparing effects of obesity treatment with very low energy diet and bariatric surgery after 2 years: a prospective cohort study

ObjectivesTo compare long-term effects and complications of medical treatment (MT) of obesity including very low energy diet with bariatric surgery.Design and settingThis prospective study conducted in a clinical setting recruited individuals with body mass index (BMI) ≥35 kg/m2 referred for obesity treatment. Demographic and anthropometric data, laboratory samples, and questionnaire replies were collected at baseline and 2 years.Participants and interventions971 individuals were recruited 2015–2017. 382 received MT, 388 Roux-en-Y gastric bypass (RYGB) and 201 sleeve gastrectomy (SG).Main outcome measuresPrimary outcomes included changes in anthropometric measures, metabolic variables and safety. These were analysed using a linear regression model. A logistic regression model was used to analyse composite variables for treatment success (secondary outcomes). A random forest (RF) model was used to examine the importance of 15 clinical domains as predictors for successful treatment.ResultsTwo-year data were available for 667 individuals (68.7%). Regarding primary outcomes, the decrease in excess BMI was 27.5%, 82.5% and 70.3% and proportion achieving a weight of >10% was 45.3%, 99.6% and 95.6% for MT, RYGB and SG, respectively (p