A randomized clinical trial comparing low-glycemic index versus ADA dietary education among individuals with type 2 diabetes

Nutrition. 2008 Jan;24(1):45-56. doi: 10.1016/j.nut.2007.10.008.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Aged
  • Blood Glucose / metabolism
  • Body Mass Index
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / diet therapy*
  • Diet, Diabetic*
  • Exercise / physiology
  • Female
  • Glycated Hemoglobin A / analysis*
  • Glycemic Index*
  • Humans
  • Hypoglycemic Agents / therapeutic use
  • Linear Models
  • Lipoproteins, HDL / blood
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Nutritional Sciences / education
  • Odds Ratio
  • Treatment Outcome
  • Triglycerides / blood
  • Weight Loss


  • Blood Glucose
  • Glycated Hemoglobin A
  • Hypoglycemic Agents
  • Lipoproteins, HDL
  • Triglycerides