Bariatric surgery is currently the most effective treatment for obesity. Since it has been shown that bariatric surgery promotes remission or improvement of comorbidities associated with obesity, such as type 2 diabetes, hypertension, dyslipidemia, and obstructive sleep apnea, the concept has migrated to metabolic surgery, and it has been included in the diabetes type 2 treatment algorithm by leading diabetes organizations. There are several surgical techniques approved by the medical authorities, each one with different outcomes and complications. Roux-en-Y gastric bypass is still the gold standard; nevertheless, sleeve gastrectomy is the most frequently performed. The restrictive and malabsorptive components that accompany the manipulation of the gastrointestinal (GI) tract do not completely explain the metabolic outcomes, and thus, multiple hormones, peptides, biliary acid metabolites, and gut microbiota composition have been found to be associated with metabolic modifications. Since its emergence, bariatric surgery has been influenced by technology, and currently, new evolving techniques are being developed and tested. Finally, to date, bariatric-metabolic surgery has been proved to be the standard of care for type 2 diabetes in obese subjects; however, research derived from bariatric centers will give rise to new techniques, less invasiveness, and the future possibility to get a wider variety of tools to prevent and to treat obesity and its metabolic abnormalities.