The governing criteria for bariatric surgery dates back from 1991 and is based solely on body mass index (BMI) as the primary operative criterion, restricting surgery to severely obese patients. Although this was a tremendous step forward in standardizing practice, these guidelines now have important limitations. During the two decades since they were crafted, bariatric surgery has evolved. Also, new procedures are now being performed, as demonstrated by level-1 evidence from randomized controlled trials comparing surgical versus clinical approaches to obesity and related diseases. Although simple and inexpensive, BMI is not a good tool to choose the best treatment option. There is little doubt that BMI alone is not an appropriate indication for surgery and could exclude many patients who could benefit from this life-saving treatment, especially patients with T2DM and lower BMIs. In this matter, new guidelines are urgently needed in order to guarantee, regulate, and reimburse metabolic surgery.