Six years ago, when JAMA last published a theme issue on obesity, there was optimism that progress was being made in preventing and treating obesity. 1 As time has passed, so too has the optimism, as reports continued to show that the prevalence of obesity was increasing 2 and, most important, rapidly increasing in children. 3 A year and a half ago, there was a call to reconsider obesity and view it in new ways with the hope of better managing this very consequential clinical problem. 4 In response, JAMA has revisited obesity in the form of a theme issue.This issue of JAMA includes 5 Original Investigations about bariatric surgery. Despite many bariatric surgery publications, most studies are not definitive due to lack of complete or long-term follow-up. 5 Relatively few randomized trials have been conducted and, of those, not many involve multiple surgeons or institutions. The 5 studies published in this week's JAMA overcome some of these limitations. 6-10 Three randomized clinical trials were performed in multiple centers, with surgery performed by several different physicians. Each trial presents 5-year outcome data with very little loss to follow-up. Two observational studies compared bariatric surgery outcomes with either specialized obesity management or usual care and also have 4-to 5-year outcomes, with nearly complete follow-up.Three of the Original Investigations in this issue of JAMA provide important information about the laparoscopic gastric sleeve operation. [6][7][8] This procedure is relatively easy to perform and has rapidly become one of the most commonly performed bariatric procedures, despite the lack of high-quality evidence to support its use. The articles in this issue demonstrate that outcomes for gastric sleeve resection (including survival, excess BMI or weight loss, and improvement of comorbidities) are nearly as good as they are for Roux-en-Y gastric bypass, and that these outcomes are durable. Despite Roux-en-Y gastric bypass being a more complicated and technically difficult operation to perform, long-term complication rates are about the same for the 2 procedures. Although laparoscopic sleeve resection has good outcomes, a substantial number of patients develop gastroesophageal reflux disease after the procedure. 6,7 Considering all the evidence, it is clear that laparoscopic gastric sleeve resection is a reasonable approach for treating significant obesity. However, as discussed in an accompanying Editorial by Arterburn