2.2. Human studies

We conducted a prospective, non-randomized study of severely obese male and female patients undergoing three different weight loss interventions: dietary program, sleeve gastrectomy, and Roux-en-Y gastric bypass. The study was approved by the St Vincent's Hospital (Sydney, NSW) Human Research Ethics Committee in accordance with national guidance and all study participants signed written consent. The subjects were recruited in Sydney from Obesity Clinics at Royal Prince Alfred and Royal North Shore Hospitals as well as from private bariatric clinics at St George Private and St Vincent's Hospitals between October 2009 and May 2012. Inclusion criteria for the study were age between 18 and 70 years, a body mass index (BMI) > 35 or BMI > 30 with medical complications from obesity. Women were either premenopausal or at least 5 years post menopause to avoid confounding by menopausal bone loss. Exclusion criteria were pregnancy and/or use of bone active (e.g. anti-resorptive) therapy. 22 patients who fulfilled the inclusion criteria were included in this study. The diet group underwent a weight loss program (Optifast® VLCD™ Program) under the care of their treating physician and dietician. Surgical procedures were performed according to currently accepted surgical techniques [12], [13], [14].