Obesity is an important public health priority in the United States. One third of U.S. adults are obese and therefore can expect higher rates of diabetes mellitus, other obesity-related comorbidities, and mortality. In 2013, the American Association of Clinical Endocrinologists, the Obesity Society, and the American Society for Metabolic and Bariatric Surgery issued a guideline that recommended weight loss (bariatric) surgery for all patients with a body mass index (BMI) of 40 kg/m2 or higher and for those with a BMI of 35 kg/m2 or greater in the presence of at least 1 obesity-related comorbidity. Among the 3 most commonly performed surgeries, the amount of excess weight reduction ranges from 49% for laparoscopic adjustable gastric banding to 76% for Roux-en-Y gastric bypass. In accredited centers, perioperative mortality averages 0.3%. In this Beyond the Guidelines, 2 experts in obesity management, a bariatric surgeon and a general internist, discuss the role of weight loss surgery versus dietary and lifestyle modification, both in general and for a specific patient who is eligible for surgery. Ethnic and age-related variability in the effects of obesity on mortality, as well as potential long-term benefits and risks of weight loss surgery for patient subgroups, are discussed.