A glucose reference curve is the optimum method to determine the glycemic glucose equivalent values of foods in humans

The glycemic index ranks carbohydrates in foods on the basis of the blood glucose response they produce for a given amount of carbohydrate. The glycemic glucose equivalents (GGEs) is the blood glucose response to a defined portion of food. The purpose of this study was to determine the best method by which to measure the GGE of a food; whether it can be estimated from 1 or 2 glucose references or if a range of glucose references should be measured. Twenty individuals without diabetes participated. The incremental area under the curve (iAUC) from fasting to at least 120 minutes after consumption of 5 foods was determined. The iAUC for different glucose amounts was also determined and a standard glucose curve of glucose level against iAUC generated. The GGE of each food was estimated from iAUC of test food using the standard curve. The study found that using a glucose reference closest to the available carbohydrate content of the food gave a mean difference (95% confidence interval) in GGEs of 3.4 (2.0-4.8) g in comparison to the standard curve. Using a 50-g glucose reference gave a mean difference in GGEs of 5.2 (4.7-5.6) g and interpolating from 2 glucose references, 3.5 (1.9-5.2) g in comparison to the standard curve. In conclusion, the best method to determine the GGE value of a food is to use the standard glucose reference curve and estimate the response of the food directly from this.