Research Article

Nutritional correlates of dietary glycaemic index: new aspects from a population perspective

Mandy Schulz^a1a2, Angela D. Liese^a2 c1, Elizabeth J. Mayer-Davis^a2a3, Ralph B. D'Agostino Jr^a4, Fang Fang^a2, Karen C. Sparks^a2 and Thomas M. Wolever^a5

^a1 Department of Epidemiology, German Institute of Human Nutrition, Potsdam-Rehbruecke, 14558 Nuthetral, Germany

^a2 Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, 800 Sumter Street, Columbia, SC 29208, USA

^a3 Center for Research in Nutrition and Health Disparities, Arnold School of Public Health, University of South Carolina, Columbia, SC 29208, USA

^a4 Department of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA

^a5 Department of Nutritional Sciences, University of Toronto, Toronto, MSS 3E2, Canada

Abstract

The role of dietary glycaemic index (GI) and glycaemic load (GL) in disease aetiology is of increasing interest. However, nutritional factors related to dietary GI and GL are not well understood from a population perspective. We aimed to investigate the relation ship between GI and GL and dietary intake at the food and nutrient level. Study subjects were 1071 non-diabetic adults from the Insulin Resistance Atherosclerosis Study, Exam I, 1992–4. Usual dietary intake was assessed with a 114-item modified Block food frequency questionnaire. Published GI values were assigned to food line items. Correlation and regression analyses were conducted. Intake of white bread, beer, meats and fries/fried potatoes was positively associated with average GI, as was fat, starch and alcohol intake (before and after energy adjustment). Intake of fruits and low-fat milk was inversely associated with GI, as were intakes of mono- and disaccharides, and fibre. GL was positively correlated with carbohydrate foods and inversely with non-carbohydrate foods. Gender-specific regression models identified eight food groups explaining 63 % (men) and 55 % (women) total GI variation after adjusting for demographics; 70 % of variation in GL was explained by eleven (men) and nine (women) food groups, respectively. Although the GI of a food is an indicator of the ability of carbohydrates to raise blood glucose, dietary GI, unlike GL, appears to reflect more dimensions of diet than just carbohydrates, such as the combination of foods consumed. This may have implications for the interpretation of dietary GI in epidemiologic studies.

(Received October 28 2004)

(Revised April 14 2005)

(Accepted April 21 2005)

Key Words:

• IRAS;
• Glycaemic index;
• Glycaemic load;
• Diet;
• Food groups;
• Nutrients

Correspondence:

^c1 *Corresponding author: Dr Angela D. Liese, fax +1 (803) 777 2524, email liese@sc.edu