Labelling of foods for glycaemic index — advantages and problems

Abstract

Food labelling has two aims — to inform the consumer of the composition of the food, and to assist him/her in the selection of a healthy diet. Labelling of foods and food products for the glycaemic index (GI) informs consumers how to choose carbohydrate-containing foods or beverages based on physiological effects. Requirements of a possible GI label should be rigorously examined and recommendations made to relevant bodies for consideration. Only foods/beverages that make a meaningful contribution to dietary carbohydrate intake should be labelled. Clear directions are needed regarding standardised methodology in accredited laboratories, including clarity on issues such as the reference (standard), total (‘available’) carbohydrate of the test food, number and characteristics of experimental subjects, capillary versus venous blood samples, analytical method for determination of blood glucose value and method of calculation of the area under the glucose curve. Furthermore, it will have to be decided whether the label should indicate low, moderate or high GI with the reference ranges or the specific number, using the standard deviation or 95% confidence interval to illustrate individual variation. The short- and long-term effects of low- and high-GI foods, and the place of each in the context of both the other nutrient contributions of the food and the total diet, should be understood by the consumer. This is a major challenge.