Effect of Brown Rice, White Rice, and Brown Rice with Legumes on Blood Glucose and Insulin Responses in Overweight Asian Indians: A Randomized Controlled Trial

Abstract

ACKGROUND: Improving the carbohydrate quality of the diet by replacing the common cereal staple white rice (WR) with brown rice (BR) could have beneficial effects on reducing the risk for diabetes and related complications. Hence we aimed to compare the effects of BR, WR, and BR with legumes (BRL) diets on 24-h glycemic and insulinemic responses among overweight Asian Indians. SUBJECTS AND METHODS: Fifteen overweight (body mass index, ≥23 kg/m(2)) Asian Indians without diabetes who were 25-45 years old participated in a randomized crossover study. Test meals (nonisocaloric, ad libitum) were identical except for the type of rice and the addition of legumes (50 g/day) and were provided for 5 consecutive days. Glucose profiles were assessed using the Medtronic MiniMed (Northridge, CA) iPro™2 continuous glucose monitoring device. The mean positive change from baseline glucose concentration was calculated as the daily incremental area under the curve (IAUC) on each test day for 5 days and averaged. Fasting serum insulin was measured prior to and at the end of each test diet. RESULTS: The percentage difference in 5-day average IAUC was 19.8% lower in the BR group than in the WR group (P=0.004). BRL further decreased the glycemic response (22.9% lower compared with WR (P=0.02). The 5-day percentage change in fasting insulin was 57% lower (P=0.0001) for the BR group and 54% lower for the BRL group compared with the 5-day percentage change observed in the WR group. The glycemic and insulinemic responses to the BR and BRL diets were not significantly different. CONCLUSIONS: Consumption of BR in place of WR can help reduce 24-h glucose and fasting insulin responses among overweight Asian Indians.