Effect of Dietary Macronutrient Composition on Glycemic Control and Cardiovascular Risk Factors

Dominic N. Reeds, M.D.

Project Overview
Obesity is a known risk factor for development of Type 2 diabetes mellitus (T2DM). Lifestyle changes consisting of weight loss and regular exercise are important to reduce cardiac risk and improving blood sugar control. The best diet to achieve these changes, however, is unclear. The American Diabetes Association (ADA) and the American Heart Association (AHA) recommend a weight-loss diet composed of approximately 60% carbohydrate calories, 15-20% protein calories and approximately 25% from fats.

Surprisingly, other than reduced food intake, this food plan composition is very similar to that consumed by the average American. Diets higher in protein and lower in carbohydrates may improve blood sugar and cardiac risk more than that of a standard ADA/AHA diet. We plan to perform an eight-month worksite intervention in two groups of diabetic subjects. One group will receive supervised physical activity, behavioral dietary counseling, and a high protein/low carbohydrate diet with ~30% of energy from protein (≥30 g protein/meal) 40% from carbohydrates and 30% from fat, with the goal of causing 8% weight loss. The other group will be advised to follow ADA/AHA exercise and diet guidelines. We will measure heart function and blood sugar control before and after the intervention in both groups to determine which group had the greatest benefit. This study will determine which diet has greater therapeutic value and should be recommended for people with T2DM.