Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA. wadden@pennmedicine.upenn.edu. Johns Hopkins School of Nursing, Baltimore, MD, USA. Division of Endocrinology and Metabolism, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY, USA. Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA. Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA. Department of Medicine, Division of Diabetes, Endocrinology & Metabolism, Department of Pediatrics, Department of Surgery, Vanderbilt University School of Medicine, Nashville, TN, USA. Vanderbilt Weight Loss Clinics, Vanderbilt University Medical Center, Nashville, TN, USA. Obesity Group, Department of Endocrinology, Universidade de São Paulo, São Paulo, Brazil. Eli Lilly and Company, Indianapolis, IN, USA.