Bariatric surgery has become the medical profession’s go-to solution for meaningful weight loss, and new research shows why: It saves lives. In a retrospective study of close to 34,000 Israeli patients with obesity, the 8,385 who got one of three surgical procedures were roughly two times less likely to die over the next four years than were obese patients whose doctors gave them only weight-loss advice and encouragement. It didn’t matter whether patients opted for gastric bypass surgery, laparoscopic banding or laparoscopic sleeve gastrectomy.