Dietary Glycemic Index, Glycemic Load, Fiber, Simple Sugars, and Insulin Resistance

The Inter99 study

  1. Cathrine Lau, MSC12,
  2. Kristine Færch, MSC12,
  3. Charlotte Glümer, MD, PHD13,
  4. Inge Tetens, MSC, PHD2,
  5. Oluf Pedersen, MD, DMSC14,
  6. Bendix Carstensen, MSC1,
  7. Torben Jørgensen, MD, DMSC3 and
  8. Knut Borch-Johnsen, MD, DMSC1
  1. 1Steno Diabetes Center, Gentofte, Denmark
  2. 2Department of Human Nutrition, LMC Centre for Advanced Food Studies, the Royal Veterinary and Agricultural University, Frederiksberg, Denmark
  3. 3Research Centre for Prevention and Health, Glostrup, Denmark
  4. 4Faculty of Health, University of Aarhus, Aarhus, Denmark
  1. Address correspondence and reprint requests to Cathrine Lau, MSC, Steno Diabetes Center, Niels Steensens Vej 2, DK-2820 Gentofte, Denmark. E-mail: cala{at}


OBJECTIVE—To examine the relationship between daily glycemic index, daily glycemic load, simple sugars, dietary fiber, and the prevalence of a measure of insulin resistance in 30- to 60-year-old nondiabetic Danish men and women.

RESEARCH DESIGN AND METHODS—The Inter99 study is a nonpharmacological intervention study. We used baseline data and examined cross-sectional associations between carbohydrate-related dietary factors and an estimate of insulin resistance in 5,675 subjects at 30–60 years. The dietary intake was estimated from a self-administered food frequency questionnaire, and insulin resistance was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). Multiple regressions were performed with HOMA-IR as the dependent variable and carbohydrate-related factors as explanatory variables. All models were adjusted for age, sex, smoking, physical activity, total energy intake, BMI, and waist circumference.

RESULTS—Intake of lactose was positively associated with HOMA-IR (P < 0.0001), whereas daily glycemic load and intake of glucose, fructose, dietary fiber, total carbohydrate, fruit, and vegetables were inversely associated with HOMA-IR (P < 0.05). Intake of dietary fiber explained the associations with daily glycemic load and total carbohydrate and attenuated the association with fruit and vegetables. No significant associations were observed for daily glycemic index or sucrose.

CONCLUSIONS—Habitual intake of diets with a high glycemic index and high glycemic load or diets with a high content of total carbohydrate including simple sugars was not associated with the probability of having insulin resistance. Furthermore, intake of dietary fiber was inversely associated with the probability of having insulin resistance.


  • C.L. has received research support from the Danish Research Agency, Ministry of Science Technology and Innovation. C.G., B.C., and K.B.-J. hold stock in and have received research support from Novo Nordisk.

    A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.

    • Accepted March 11, 2005.
    • Received February 2, 2005.
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