The glycemic index was first conceived in Australia and today, that nation remains the center of most GI research with the Sydney University Glycemic Index Research Service (SUGiRS) being the ultimate world authority on the subject. Why does any of this matter? Because GI is confusing and often mis-measured and misapplied so that unless we fall back upon a strict and precise standard, GI will simply become another meaningless buzzword. Therefore, at the outset of this discussion let me state that everything I have to say on the subject is based solely upon the standards set forth by the SUGiRS.
SUGiRS works closely with an Australian organization called the "Glycemic Index Foundation" and together, using the former's data and the latter's resources they have published the largest Glycemic Index database in the world. This database is available online here.
The official seal of the Australian Glycemic Index Foundation (shown at left) appears to be a highly coveted label for many food products sold in that country. In order for a food to receive this label it appears that companies must perform a rather extensive series of tests upon these products and pay both the foundation and "certified" laboratories. This causes me a slight degree of concern that the label may be more a vehicle for profit than a useful tool for consumers, particularly since glycemic load matters so much too.