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.