A new study published in Metabolism tested the hypothesis that a whole-grain (WG) diet reduces insulin resistance and improves glucose use in individuals at risk for type-2 diabetes, when compared to an isocaloric-matched refined-grain diet. This double-blinded, randomized, controlled, crossover trial recruited 14 moderately obese adults, with a mean age of 38±2 years and mean BMI of 34.0±1.1kg/m². These patients were given diets containing either whole-grain (50g per 1000kcal) or equivalent refined-grain, for 8 weeks with an 8-10 week wash out period between diets, both of which met ADA nutritional guidelines. The results revealed that post-prandial glucose tolerance, peripheral insulin sensitivity, and metabolic flexibility (insulin-stimulated-fasting carbohydrate oxidation) improvements were greater after whole-grain diet than after the refined-grain diet. Additionally, compared to baseline, body fat and hepatic R_a insulin resistance was reduced by both diets. In contrast, fasting glucose and exogenous glucose-meal remained unchanged after both the interventions. Furthermore, the changes in peripheral insulin resistance and metabolic flexibility correlated with improved glucose tolerance. Thus, it was inferred that a whole-grain diet reduced diabetes risk and the mechanisms appear to work via reduced post-prandial blood glucose and peripheral insulin resistance that could be statistically linked to enhanced metabolic flexibility.