GCG and type 2 diabetes mellitus: Although the physio-pathological mechanisms underlying the metabolic effects of bariatric surgery are complex (and continue to receive research attention), T2DM remission appears to be related to an absence of the anti-incretin effect, which is attributed to a proximal jejunum exclusion and a lower oxidation of free fatty acids, changes in gut flora, together with an early and elevated post-prandial secretion of GLP1 that occurs a few weeks post-bariatric surgery [16,17].