Whey protein is an excellent source of fast absorbing high-quality protein, which makes it an ideal pre- and post-workout nutrition strategy. A recent study has discovered another advantage of whey protein, it promotes insulin secretion and function. In this study, subjects were provided a breakfast (bread, ham, and lactose) and lunch (mashed potatoes, meatballs, ham, and lactose) with fast-absorbing high-glycemic index carbohydrates and the glucose and insulin responses to the meals were measured. On another occasion, the same test meals were consumed, but whey protein (18.2 g protein and 5.3 g lactose) was exchanged for the lactose and ham so that energy, protein, carbohydrate, and fat were identical. Compared to the normal meals, the whey containing meals resulted in a significantly higher insulin response at breakfast (31%) and lunch (57%), which led to a significantly lower glucose response at lunch (-21%). Thus, whey protein augments insulin secretion, which led to improved disposal of glucose. Insulin also promotes disposal of amino acids, although this was not measured in this study. The implications of this research are that whey protein is an ideal supplement to include with meals and as a post-exercise drink because it augments insulin-mediated disposal of glucose and amino acids.

Frid AH, Nilsson M, Holst JJ, Bjorck IM. Effect of whey on blood glucose and insulin responses to composite breakfast and lunch meals in type 2 diabetic subjects. Am J Clin Nutr. 2005 Jul;82(1):69-75.