Ketogenic Diet Treatment of Obesity With Co-morbid Type 2 Diabetes Mellitus and/or Obstructive Sleep Apnea

The purpose of the study is to evaluate the efficacy and safety of ketogenic diet (KD) treatment of (i) obesity, (ii) type 2 diabetes mellitus and (iii) obstructive sleep apnea (OSA) in patients with obesity and Type 2 DM and in patients with obesity and/or OSA. This will be a randomized, open-label three arm controlled study comparing weight loss in obese participants with type 2 diabetes and/or obstructive sleep apnea treated for 9 months with 3:1 \[fat\]:\[protein+carbohydrate\] ratio, 1600 kcal/day diet (Group A) with weight loss in participants treated with orlistat 120 mg TID and lifestyle intervention consisting of dietary advice, recommended caloric goal of 1600 kcal/day (Group B), and in participants treated with only lifestyle intervention consisting of dietary advice, recommended caloric goal of 1600 kcal/day (Group C).