Glycemic index, glycemic load, and risk of type 2 diabetes: results from 3 large US cohorts and an updated meta-analysis

Am J Clin Nutr. 2014 Jul;100(1):218-32. doi: 10.3945/ajcn.113.079533. Epub 2014 Apr 30.


Background: Epidemiologic evidence for the relation between carbohydrate quality and risk of type 2 diabetes (T2D) has been mixed.

Objective: We prospectively examined the association of dietary glycemic index (GI) and glycemic load (GL) with T2D risk.

Design: We prospectively followed 74,248 women from the Nurses' Health Study (1984-2008), 90,411 women from the Nurses' Health Study II (1991-2009), and 40,498 men from the Health Professionals Follow-Up Study (1986-2008) who were free of diabetes, cardiovascular disease, and cancer at baseline. Diet was assessed by using a validated questionnaire and updated every 4 y. We also conducted an updated meta-analysis, including results from our 3 cohorts and other studies.

Results: During 3,800,618 person-years of follow-up, we documented 15,027 cases of incident T2D. In pooled multivariable analyses, those in the highest quintile of energy-adjusted GI had a 33% higher risk (95% CI: 26%, 41%) of T2D than those in the lowest quintile. Participants in the highest quintile of energy-adjusted GL had a 10% higher risk (95% CI: 2%, 18%) of T2D. Participants who consumed a combination diet that was high in GI or GL and low in cereal fiber had an ~50% higher risk of T2D. In the updated meta-analysis, the summary RRs (95% CIs) comparing the highest with the lowest categories of GI and GL were 1.19 (1.14, 1.24) and 1.13 (1.08, 1.17), respectively.

Conclusion: The updated analyses from our 3 cohorts and meta-analyses provide further evidence that higher dietary GI and GL are associated with increased risk of T2D.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood Glucose / metabolism*
  • Diabetes Mellitus, Type 2 / epidemiology*
  • Diabetes Mellitus, Type 2 / prevention & control*
  • Energy Intake
  • Follow-Up Studies
  • Glycemic Index*
  • Humans
  • Incidence
  • Nutrition Assessment
  • Reproducibility of Results
  • Risk Factors
  • Surveys and Questionnaires
  • United States / epidemiology


  • Blood Glucose