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Determination of the glycaemic index of foods: interlaboratory study


Objective: Practical use of the glycaemic index (GI), as recommended by the FAO/WHO, requires an evaluation of the recommended method. Our purpose was to determine the magnitude and sources of variation of the GI values obtained by experienced investigators in different international centres.

Design: GI values of four centrally provided foods (instant potato, rice, spaghetti and barley) and locally obtained white bread were determined in 8–12 subjects in each of seven centres using the method recommended by FAO/WHO. Data analysis was performed centrally.

Setting: University departments of nutrition.

Subjects: Healthy subjects (28 male, 40 female) were studied.

Results: The GI values of the five foods did not vary significantly in different centres nor was there a significant centre×food interaction. Within-subject variation from two centres using venous blood was twice that from five centres using capillary blood. The s.d. of centre mean GI values was reduced from 10.6 (range 6.8–12.8) to 9.0 (range 4.8–12.6) by excluding venous blood data. GI values were not significantly related to differences in method of glucose measurement or subject characteristics (age, sex, BMI, ethnicity or absolute glycaemic response). GI values for locally obtained bread were no more variable than those for centrally provided foods.

Conclusions: The GI values of foods are more precisely determined using capillary than venous blood sampling, with mean between-laboratory s.d. of approximately 9.0. Finding ways to reduce within-subject variation of glycaemic responses may be the most effective strategy to improve the precision of measurement of GI values.

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  • Abdallah, L, Chabert, M & Louis-Sylvestre, (1997). Cephalic phase responses to sweet taste. Am. J. Clin. Nutr., 65, 737–743.

    Article  CAS  Google Scholar 

  • Åkerberg, A, Liljeberg, H & Björck, I (1998). An in vitro method based on chewing, to predict resistant starch content in foods allows parallel determination of potentially available starch and dietary fiber. J. Nutr., 128, 651–660.

    Article  Google Scholar 

  • Allison, DB, Paultre, F, Goran, MI, Poehlman, ET & Heynsfield, SB (1995). Statistical considerations regarding the use of ratios to adjust data. Int. J. Obes. Relat. Metab. Disord., 19, 644–652.

    CAS  PubMed  Google Scholar 

  • AOAC (1995). Official Methods of Analysis, 16th edn. Arlington, VA: Association of Official Analytical Chemists

  • Björck, I, Granfeldt, Y, Liljeberg, H, Tovar, J & Asp, N-G (1994). Food properties affecting the digestion and absorption of carbohydrates. Am. J. Clin. Nutr., 59, (Suppl) 696S–705S.

    Google Scholar 

  • Brand, JC, Colagiuri, S, Crossman, S, Allan, A, Roberts, DCK & Truswell, AS (1991). Low-glycemic index foods improve long-term glycemic control in NIDDM. Diabetes Care, 14, 95–101.

    Article  CAS  Google Scholar 

  • Brand-Miller, J, Foster-Powell, K & Colagiuri, S (1996). The GI Factor, Hodder: Sydney

    Google Scholar 

  • Coppack, SW, Fisher, RM, Gibbons, GF, Humphreys, SM, McDonough, MJ, Potts, JL & Frayn, KN (1990). Postprandial substrate deposition in human forearm and adipose tissue in vivo. Clin. Sci., 79, 339–348.

    Article  CAS  Google Scholar 

  • Englyst, HN, Kingman, SM & Cummings, JH (1992). Classification and measurement of nutritionally important starch fractions. Eur. J. Clin. Nutr., 46, S33–S50.

    PubMed  Google Scholar 

  • FAO/WHO (1998). Carbohydrates in Human Nutrition, FAO Food and Nutrition Paper 66 Rome: FAO

  • Foster-Powell, K & Brand-Miller, J (1995). International tables of glycemic index. Am. J. Clin. Nutr., 62, 871S–893S.

    Article  CAS  Google Scholar 

  • Frost, G, Wilding, J & Beecham, J (1994). Dietary advice based on the glycaemic index improves dietary profile and metabolic control in type 2 diabetic patients. Diabetic Med., 11, 397–401.

    Article  CAS  Google Scholar 

  • Frost, G, Leeds, A, Trew, G, Margara, R & Dornhorst, A (1998). Insulin sensitivity in women at risk of coronary heart disease and the effect of a low glycemic diet. Metabolism, 47, 1245–1251.

    Article  CAS  Google Scholar 

  • Frost, G, Leeds, AA, Doré, CJ, Madeiros, S, Brading, S & Dornhorst, A (1999). Glycaemic index as a determinant of serum HDL-cholesterol concentration. Lancet, 353, 1045–1048.

    Article  CAS  Google Scholar 

  • Gilbertson, HR, Brand-Miller, JC, Thorburn, AW, Evans, S, Chondros, P & Werther, GA (2001). The effect of flexible low glycemic index dietary advice vs measured carbohydrate exchange diets on glycemic control in children with type 1 diabetes. Diabetes Care, 24, 1137–1143.

    Article  CAS  Google Scholar 

  • Jackson, RA, Peters, N, Advani, U, Perry, G, Rogers, J, Brough, WH & Pilkington, TRE (1973). Forearm glucose uptake during the oral glucose tolerance test in normal subjects. Diabetes, 22, 442–458.

    Article  CAS  Google Scholar 

  • Järvi, AE, Karlström, BE, Granfeldt, YE, Björck, IE, Asp, N-G & Vessby, BOH (1999). Improved glycemic control and lipid profile and normalized fibrinolytic activity on a low-glycemic index diet in type 2 diabetic patients. Diabetes Care, 22, 10–18.

    Article  Google Scholar 

  • Jenkins, DJA, Wolever, TMS, Kalmusky, J, Guidici, S, Giordano, C, Patten, R, Wong, GS, Bird, JN, Hall, M, Buckley, G, Csima, A & Little, JA (1987a). Low-glycemic index diet in hyperlipidemia: use of traditional starchy foods. Am. J. Clin. Nutr., 46, 66–71.

    Article  CAS  Google Scholar 

  • Jenkins, DJA, Wolever, TMS, Collier, GR, Ocana, A, Rao, AV, Buckley, G, Lam, KY, Meyer, A & Thompson, LU (1987b). The metabolic effects of a low glycemic index diet. Am. J. Clin. Nutr., 46, 968–975.

    Article  CAS  Google Scholar 

  • Liu, S, Willett, WC, Stampfer, MJ, Hu, FB, Franz, M, Sampson, L, Hennekens, CH & Manson, JE (2000). A prospective study of dietary glycemic load, carbohydrate intake and risk of coronary heart disease in US women. Am. J. Clin. Nutr., 71, 1455–1461.

    Article  CAS  Google Scholar 

  • Matthews, DR, Lang, DA, Burnett, M & Turner, RC (1983). Control of pulsatile insulin secretion in man. Diabetologia, 24, 231–237.

    Article  CAS  Google Scholar 

  • Salmerón, J, Manson, JE, Stampfer, MJ, Colditz, GA, Wing, AL & Willett, WC (1997a). Dietary fiber, glycemic load, and risk on non-insulin-dependent diabetes mellitus in women. JAMA, 277, 472–477.

    Article  Google Scholar 

  • Salmerón, J, Ascherio, A, Rimm, EB, Colditz, GA, Spiegelman, D, Jenkins, DJ, Stampfer, MJ, Wing, AL & Willett, WC (1997b). Dietary fiber, glycemic load, and risk of NIDDM in men. Diabetes Care, 20, 545–550.

    Article  Google Scholar 

  • Soh, NL & Brand-Miller, J (1999). The glycaemic index of potatoes: the effect of variety, cooking method and maturity. Eur. J. Clin. Nutr., 53, 249–254.

    Article  CAS  Google Scholar 

  • Thomas, DE, Brotherhood, JR & Brand, JC (1991). Carbohydrate feeding before exercise: effect of glycemic index. Int. J. Sports Med., 12, 180–186.

    Article  CAS  Google Scholar 

  • Wolever, TMS (1992). Glycemic index vs glycemic response: non-synonymous terms. Diabetes Care, 15, 1436–1437.

    Article  CAS  Google Scholar 

  • Wolever, TMS & Bolognesi, C (1996). Source and amount of carbohydrate affect postprandial glucose and insulin in normal subjects. J. Nutr., 126, 2798–2806.

    CAS  PubMed  Google Scholar 

  • Wolever, TMS, Jenkins, DJA, Vuksan, V, Josse, RG, Wong, GS & Jenkins, AL (1990). Glycemic index of foods in individual subjects. Diabetes Care, 13, 126–132.

    Article  CAS  Google Scholar 

  • Wolever, TMS, Jenkins, DJA, Jenkins, AL & Josse, RG (1991). The glycemic index: methodology and clinical implications. Am. J. Clin. Nutr., 54, 846–854.

    Article  CAS  Google Scholar 

  • Wolever, TMS, Jenkins, DJA, Vuksan, V, Jenkins, AL, Wong, GS & Josse, RG (1992a). Beneficial effect of low-glycemic index diet in overweight NIDDM subjects. Diabetes Care, 15, 562–566.

    Article  CAS  Google Scholar 

  • Wolever, TMS, Jenkins, DJA, Vuksan, V, Jenkins, AL, Buckley, GC, Wong, GS & Josse, RG (1992b). Beneficial effect of a low-glycaemic index diet in type 2 diabetes. Diabetic Med., 9, 451–458.

    Article  CAS  Google Scholar 

  • Wolever, TMS, Katzman-Relle, L, Jenkins, AL, Vuksan, V, Josse, RG & Jenkins, DJA (1994). Glycaemic index of 102 complex carbohydrate foods in patients with diabetes. Nutr. Res., 4, 651–669.

    Article  Google Scholar 

  • Zar, JH (1984). Biostatistical Analysis, 2nd edn. Englewood Cliffs, NJ: Prentice Hall

    Google Scholar 

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Supported by Glycaemic Index Testing Inc., Toronto; Australian Research Council; University of Parma, Italy; Department of Human Nutrition, University of Otago; University of the West Indies; Nestlé South Africa, the Sugar Association of South Africa and the National Research Association of South Africa.

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Guarantor: TMS Wolever.

Contributors: TMSW coordinated the study, did the statistical analysis and drafted the manuscript. TMSW and HHV conceived of the overall study and were responsible for raising funds and planning the studies at their local sites. IB, JBM, FB, JIM and DDR (whose names are listed in alphabetical order) were responsible for raising funds and planning the studies at their local sites. YG, SH, TLP, CV and XW were responsible for implementing the studies at their local sites. All contributors helped with the revision of the paper.

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Correspondence to T M S Wolever.

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Wolever, T., Vorster, H., Björck, I. et al. Determination of the glycaemic index of foods: interlaboratory study. Eur J Clin Nutr 57, 475–482 (2003).

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