Protein’s unique ability to differentially modify post prandial glycemic responses makes it a potential tool that could help individuals with diabetes (or prediabetes) manage their blood glucose levels after meals or when they perform physical activity, with the former situation requiring more insulin secretion to limit hyperglycemia, and the later typically requiring less insulin secretion and a significant rise in glucagon secretion into the hepatic portal vein to facilitate hepatic glucose production to help limit exercise-induced hypoglycemia. This evidence concerns the gene GCG and diabetes mellitus.