It has been reported that 55 g of whey preload reduced the glycemic response to a mashed potato meal consumed later in type 2 diabetic patients, and the result was attributed to delayed gastric emptying and sustained release of gut-derived signals including glucagon-like peptide-1 (GLP-1), cholecystokinin (CCK), and glucose-dependent insulinotropic polypeptide (GIP) [33]. Here, GIP is linked to type 2 diabetes mellitus.