Objective: We compared the effects of a low glycemic index (GI) diet with the American Diabetes Association (ADA) diet on glycosylated hemoglobin (HbA1c) among individuals with type 2 diabetes.
Methods: Forty individuals with poorly controlled type 2 diabetes were randomized to a low-GI or an ADA diet. The intervention, consisting of eight educational sessions (monthly for the first 6 mo and then at months 8 and 10), focused on a low-GI or an ADA diet. Data on demographics, diet, physical activity, psychosocial factors, and diabetes medication use were assessed at baseline and 6 and 12 mo. Generalized linear mixed models were used to compare the two groups on HbA1c, diabetic medication use, blood lipids, weight, diet, and physical activity.
Results: Participants (53% female, mean age 53.5 y) were predominantly white with a mean body mass index of 35.8 kg/m(2). Although both interventions achieved similar reductions in mean HbA1c at 6 mo and 12 mo, the low-GI diet group was less likely to add or increase dosage of diabetic medications (odds ratio 0.26, P = 0.01). Improvements in high-density lipoprotein cholesterol, triacylglycerols, and weight loss were similar between groups.
Conclusion: Compared with the ADA diet, the low-GI diet achieved equivalent control of HbA1c using less diabetic medication. Despite its limited size, this trial suggests that a low-GI diet is a viable alternative to the ADA diet. Findings should be evaluated in a larger randomized controlled trial.