Decades of physiological studies and recent results of gastric bypass surgery emphasize the significance of gut hormones in control of pancreatic beta-cell growth and secretion (the incretin effect). Of the known gut hormones GLP-1 has emerged as a major incretin. But GLP-1 cannot alone explain the gut hormonal effects of bariatric surgery. In the recent search of additional incretins, gastrin and perhaps CCK seem worth a re-evaluation. Both are insulinotropic, in particular during protein and fat-rich meals. Recent results also indicate a potent synergistic interaction with GLP-1 in the effect of pancreatic islet cells. Re-evaluation of the roles of gastrin and CCK consequently provide new food for incretin-thoughts.