INS and type 2 diabetes mellitus: Supporting this, one study in adults with T2D comparing the glycemic response to two animal-based proteins, whey (fast-digesting) and casein (slow-digesting), found that the faster-digesting whey protein stimulated a greater insulin peak (301.4 pM vs. 215.3 pM, p<0.015) and 180 min AUC (33.2 nU/mL*180 min vs. 26.6 nU/mL*180 min, p<0.05) (26).