The Effects of a Low Carbohydrate, Non-Ketogenic Diet Versus Standard Diabetes Diet on Glycemic Control in Type 1 Diabetes

Type 1 diabetes mellitus (T1D) is marked by total insulin dependence with challenges regarding glycemic control and concomitant sequela. While standard of care medical nutrition therapy for this disease centers on matching carbohydrate to insulin at meals, recent literature and clinical reports have shown superior glycemic control and cardiovascular measures with lower carbohydrate dietary patterns (<130g/day) as compared to the standard American MyPlate (50% total calories as carbohydrate) approach. Diabetes management has evolved tremendously in the last twenty years with the development of sophisticated insulin pumps and continuous glucose monitors; but, glycemic control is still dependent on quantification of carbohydrate, imperfect in the real-world setting. Due to inherent error in carbohydrate counting, the investigators propose that less carbohydrate will produce better glycemic control by minimizing error and subsequent variation in individuals with type 1 diabetes.

There has long been a movement in the medical community to prescribe low carbohydrate diets under the premise of "less carbohydrate, less insulin, less glycemic variation". This strategy centers on "the law of small numbers", a calculus principle describing magnitude of variation in the output (glycemic variation) as the function of input size (CHO + insulin). Carbohydrate counting tends to result in ~50% error while there is ~30% variation in insulin action, making exactitude impossible. However, low CHO diets tend to provide >40% energy from fat due to the macronutrient distribution. With innate risk of cardiovascular disease in T1D, standard of care has supported restriction of total fat consumption, especially saturated fat, in effort to control cholesterol. While the American Diabetes Association recognizes that dietary fat is a controversial and complex issue, eliminating trans-fats is the only consensus point across the field. To date, most low CHO diet studies in both T1D and Type 2 Diabetes (T2D) have not shown adverse effects on lipids and tend to show decreases in triglycerides and either no change or increases in HDL, LDL, and total cholesterol.