Abstract
We conducted a randomized crossover study in 15 Japanese patients with type 2 diabetes controlled by diet to determine the effects of eating "vegetables before carbohydrates" on postprandial plasma glucose and serum insulin. Subjects ate test meals consisting of white rice and vegetables, eating either "vegetables before carbohydrates" or vice versa. Postprandial plasma glucose and serum insulin in those following the "vegetables before carbohydrates" regimen were reduced at 30 and 60 min compared to the reverse regimen. To investigate the effects of eating "vegetables before carbohydrates" on glycemic control over the long term, the impact on HbA1c was retrospectively compared in a total of 333 patients in either the "vegetables before carbohydrates" experimental group or the control group on the opposite regimen at 30 months of follow-up. Improvements in HbA1c levels over 30 months were observed from 8.3 to 7.1 % in the experimental group (p<0.001) while no change was observed in the control group. Additionally we carried out a randomized, controlled trial to determine whether educating diabetic patients to eat "vegetables before carbohydrates" was as effective as a traditional exchange-based meal plan on long-term glycemic control. A total of 101 patients were stratified according to sex, age, BMI, duration of diabetes, and HbA1c and then randomized to receive instructions to eat either "vegetables before carbohydrates" (VBC, n=69) or an exchange-based meal plan (EXB, n=32). Significant improvements in HbA1c over 24 months were observed in both groups (VBC, 8.3 to 6.8 % vs EXB, 8.2 to 7.3 %). However, HbA1c levels were significantly lower in the VBC group than in the EXB group after 6, 9, 12 and 24 months of the study. These studies demonstrate that a simple meal plan of eating "vegetables before carbohydrates" is effective for reducing the postprandial plasma glucose and glycemic control over the long term in Japanese patients with type 2 diabetes.
