Evaluation of a Lifestyle Intervention After Bariatric Surgery

People with severe obesity who are scheduled to undergo either primary gastric bypass or primary sleeve gastrectomy will be recruited from the Bariatric Clinics at University College London Hospital (UCLH) and the Whittington Hospital and asked to participate in an observational cohort study. Eligible patients will be given a participant information sheet (PIS) for BARI-LIFESTYLE Observational Study and informed consent will be sought. Recruited patient will attend for 4 research visits, timed to coincide with their clinic visits, at approximately 6 weeks before surgery (Visit 1), 3 month post-surgery (Visit 2), 6 months post-surgery (Visit 3) and 12 months post-surgery (Visit 4). Each research visit will include assessment of body weight, body composition (using bioelectrical impedance analysis), physical fitness and activity levels, obesity-associated co-morbidities, HRQoL and usual care laboratory investigations. Dual energy X-ray absorptiometry (DXA) scanning will be undertaken at Visit 1 and Visit 4, which is not a usual assessment for the post-surgery standard care. All of the research assessments will be done as part of this observational cohort study. Immediately after surgery has been undertaken, BARI-LIFESTYLE Observational Study participants will be randomised to continue to receive usual care, or usual care plus lifestyle intervention (nutritional and behavioural tele-counselling, self-monitoring and a 12-week supervised tailored exercise programme). However, to avoid contamination between the intervention group and the usual care group, only those randomly allocated to the lifestyle intervention group will be informed of this. They will be given a PIS (BARI-LIFESTYLE Intervention Study) and informed consent will be sought. If the participants decline to take part in the lifestyle programme, they will remain in the control group (observational cohort study).