GIP and type 2 diabetes mellitus: In a study with the DPP‐4 inhibitor, vildagliptin, whey preload in metformin‐treated patients enhanced the efficacy of vildagliptin by slowing gastric emptying and reducing postprandial glycaemia, in addition to increase in plasma intact GLP‐1 and GIP.99 Similarly, in T2DM patients who consumed a preload drink containing 50 g D‐xylose, level of prandial glycaemia was reduced and the effect of a DPP‐4 inhibitor, sitagliptin, was enhanced.100 Further, glycaemic control improved in patients with T2DM taking AHAs and eating glutinous brown rice (GBR) for 8 weeks.