Effect of a Low-Glycemic Index or a High-Cereal Fiber Diet on Type 2 Diabetes

Results In the intention-to-treat analysis, HbA1c decreased by �0.18% absolute HbA1c units (95% confidence interval [CI], �0.29% to �0.07%) in the high–cereal fiber diet compared with �0.50% absolute HbA1c units (95% CI, �0.61% to �0.39%) in the low–glycemic index diet (P.001). There was also an increase of high-density lipoprotein cholesterol in the low–glycemic index diet by 1.7 mg/dL (95% CI, 0.8-2.6 mg/ dL) compared with a decrease of high-density lipoprotein cholesterol by �0.2 mg/dL (95% CI, �0.9 to 0.5 mg/dL) in the high–cereal fiber diet (P=.005). The reduction in dietary glycemic index related positively to the reduction in HbA1c concentration (r=0.35, P.001) and negatively to the increase in high-density lipoprotein cholesterol (r=�0.19, P=.009). Conclusion In patients with type 2 diabetes, 6-month treatment with a low– glycemic index diet resulted in moderately lower HbA1c levels compared with a high– cereal fiber diet.