Weight-loss surgery is often heralded as a relatively risk-free procedure, especially compared to the health problems that can go hand-in-hand with obesity. But, for the heaviest among us—the so-called superobese—the decision to go under the knife is not one to be taken lightly. According to a study published in this month’s Archives of Surgery, the superobese, especially those with underlying ills, like diabetes, are far more likely to die in the months and years following surgery than those who start out weighing less. (A body-mass index greater than 50 is considered superobese.) Whereas the average 1-year mortality rate for patients undergoing bariatric surgery is estimated to be less than 1 percent per year, the superobese patients who took part in this study had a 5.2 percent risk of mortality dying within the first year—a five-fold increase. To explain the gap, the authors point out that the more sizable the patient, the more technically difficult the surgery and the greater the risk of complications. Even so, the researchers stopped short of denouncing weight-loss surgery for the biggest of the big. Instead, they note that the superobese “have a high risk of death without surgical treatment” because of their size. In the end, the investigators encourage superobese patients to weigh the potential pros and cons with their doctors before signing up for surgery.