The article by Varban et al1 in this issue of JAMA Surgery reports several findings that constitute an important contribution to the field of metabolic and bariatric surgery (MBS). These include an improved response rate for all obesity-related comorbid conditions reported among those patients who achieve a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) of less than 30 at 1 year following surgery. Patients achieving a BMI of less than 30 also self-reported superior patient satisfaction. Finally, those patients with a preoperative BMI of less than 40 were substantially more likely to achieve a BMI of less than 30 at 1 year after surgery. The authors1 correctly reported that virtually all observational reports of large series of patients who have undergone MBS report a baseline BMI in the mid- to upper 40s.2 Although weight loss is not directly reported by Varban et al,1 the implication is that patients with lower BMIs, specifically less than 40, are the optimal candidates for MBS. This conclusion is based on the present data and relies heavily on a recent study by Schauer et al3 who reported a diminishing survival benefit to MBS among patients with increasing BMI. However, the Schauer et al3 study is based on administrative data and is laden with numerous assumptions, some of which are implausible for observational data.
Wolfe BM, Walker E. It’s About the Weight Loss. JAMA Surg. Published online July 26, 2017. doi:10.1001/jamasurg.2017.2349