Glycaemic glucose equivalent: validation as a predictor of the relative glycaemic effect of foods

Abstract

Background: Glycaemic glucose equivalent (GGE) content of a quantity of a food, based on glycaemic index, food composition and food quantity, is the theoretical weight of glucose that would induce a glycaemic response equivalent to that induced by the given amount of food.

Objectives: To test whether GGE content predicts glycaemic response to foods differing in glycaemic index, carbohydrate content and intake, over a practical range of carbohydrate intakes.

Design: : Controlled randomised study.

Setting: Clinical trials unit at the Department of Human Nutrition, University of Otago, Dunedin, New Zealand.

Subjects: In all, 12 volunteers with and 12 without type II diabetes were recruited. All but one subject completed the trial.

Method: Yams, biscuits, white rice and porridge were consumed at 10 and 20 GGE doses, and 2-minute noodles at 24 and 48 GGE, following an overnight fast. Incremental areas under the blood glucose response curves (IAUC) over 3 h were calculated for each individual for all foods, and individual glycaemic responsiveness was determined as IAUC/GGE.

Results: Within GGE dose, blood glucose responses to all foods, except rice, were similar. Doubling GGE dose approximately doubled glycaemic response. Relative glycaemic effects were accurately predicted by GGE intake after adjusting for individual glycaemic sensitivity (individual average IAUC/GGE). The accuracy of prediction of relative glycaemic effect from GGE intake was affected little by carbohydrate dose.

Conclusion: GGE content predicted glycaemic impact of foods over a practical range of carbohydrate intakes, and may therefore be useful for accurate dietary management of glycaemia in diabetes mellitus. The predictive validity of GGE in mixed meals now needs to be tested.

Sponsorship: Health Research Council of New Zealand contract 00/453.