Effects of protein intake on glucagon, insulin, and glucose dynamics: implications for diabetes

Carbohydrates are the main macronutrient of interest for dosing insulin and managing glycemia in type 1 diabetes (T1D) due to their direct impact on blood glucose levels, however, the influence of protein on glycemia and pancreatic islet hormone secretions in people living with either T1D or type 2 diabetes (T2D) should not be overlooked. Protein ingestion plays a key role in the secretion of both insulin and glucagon, making it a key regulator of blood glucose levels in health and diabetes. The glycemic response to protein is affected by many factors including the protein's form, source, digestion rate, whether it is consumed on its own or in a mixed meal, as well as its timing in relation to other meals and/or physical activity. Additionally, the hormonal and glycemic response to protein differs markedly between non diabetic individuals, T1D, and T2D. The unique ability of protein to modify post-prandial glycemia makes it a potential tool that individuals with diabetes or prediabetes can utilize to help manage their own glycemia. This review will discuss the ways in which protein intake and supplementation with certain protein types may be able to improve overall glycemia and time in range for individuals living with diabetes or prediabetes.