The study concludes that there is sufficient evidence to state that acute milk protein supplementation improves insulin secretion by positively influencing postprandial glycemic values (but, at the moment, there is no long-term evidence) and that milk proteins can be a valid ally in the treatment of prediabetes and T2DM as they include amino acids and bioactive peptides capable of directly influencing gastric emptying, the secretion of incretin hormones, and the insulin response itself. Here, INS is linked to type 2 diabetes mellitus.