Diet rich in unsaturated fat may up insulin sensitivity

(HealthDay)—A diet rich in unsaturated fat may increase insulin sensitivity in individuals who are at higher risk for cardiovascular disease, according to research published in the May issue of Diabetes Care.

Meghana D. Gadgil, M.D., M.P.H., of Johns Hopkins University in Baltimore, and colleagues enrolled 164 individuals with prehypertension or stage 1 hypertension, without diabetes, in a randomized, controlled, three-period, crossover feeding study. The three diets studied were a carbohydrate-rich diet (similar to the Dietary Approaches to Stop Hypertension [DASH] diet), a protein-rich diet (predominantly from plant sources), and an unsaturated fat-rich diet (mostly monounsaturated fat). The primary outcome was calculation of the quantitative insulin sensitivity check index (QUICKI), a validated measure of insulin sensitivity.

At baseline, the researchers noted a mean body mass index of 30.2 kg/m² and a mean QUICKI of 0.35. The increase in QUICKI (0.005) was significantly greater with the unsaturated fat-rich diet compared with the carbohydrate-rich diet. The protein-rich diet had no significant effect on insulin sensitivity compared with the carbohydrate-rich diet.

"Our analysis suggests that a diet rich in unsaturated fats, which is commonplace in Mediterranean-style diets, improves insulin sensitivity in a population at risk for cardiovascular disease," the authors write.