1 March 2021



Evaluating the quality of carbohydrate in the diet could be considered more important than ever. Markers of quality such as wholegrains, fibre content and sugars are routinely included on food labels and in national food composition tables. But another marker of carbohydrate quality, the glycemic index (GI), is rarely available from these sources. Instead, informed consumers, researchers and health professionals must rely on multiple sources including papers published in the scientific literature, online databases and books such as The Shoppers Guide to GI Values. In the lucky country (Australia!) and New Zealand, GI claims are permitted on the labels of healthier foods, and a not-for-profit food endorsement charity, the GI Foundation, also promotes healthy low GI foods at the point of sale. 

The first GI values of 62 common foods using a standardized methodology were published 4 decades ago by David Jenkins, Tom Wolever and others at the University of Toronto. Since then, the University of Sydney has played an important role of compiling and updating reliable, international tables of GI values. The tables have been instrumental in improving the quality of research examining the relation between dietary glycemic potential and health. Indeed, they are among the most cited papers in the field. In 1995, there were 565 entries in the edition published in the American Journal of Clinical Nutrition. By 2002 there were 750 foods, and by 2008 there were 2487 in the third edition published in Diabetes Care. And I am pleased to say that after a long gestation, the 2021 edition with international authorship and over 4000 foods, is currently under review. 

Asian Noodles

In the meantime, our colleagues in Singapore, led by Professor Jeya Henry have published the first compendium of 940 non-Western foods, citing over 150 papers. The table includes data from Malaysia, Thailand, Indonesia, Philippines, Japan, Korea, China, Taiwan, Hong Kong, India, Sri Lanka, Emirates, Oman, Saudi Arabia, Lebanon, as well as Singapore. This is an important milestone because the vast majority of published GI values are of Western origin, notably European, Australian and North American. We know that GI values are altered by the degree of cooking and processing and this will vary from country-to-country. Moreover, in Asian countries, carbohydrate foods provide a much greater proportion of dietary energy – around 60%. Hence, the potential to reduce postprandial glycaemia by substituting high GI foods for lower GI counterparts is also magnified. Singapore has the distinction of being the only country with two GI testing services using the ISO methodology. And recently, the China National Research Institute of Food and Fermentation Industries has offered a commercial GI testing service after extensive training at the University of Sydney. In collaboration with Sydney, CNRIFFI has also translated the online 2008 International Tables of GI and glycemic load into Chinese. We hope these wonderful developments will translate into healthier carbohydrate food offerings throughout Asia, the Middle East and beyond. 

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Professor Jennie Brand-Miller       
Professor Jennie Brand-Miller holds a Personal Chair in Human Nutrition in the Charles Perkins Centre and the School of Life and Environmental Sciences, at the University of Sydney. She is recognised around the world for her work on carbohydrates and the glycemic index (or GI) of foods, with over 300 scientific publications. Her books about the glycemic index have been bestsellers and made the GI a household word.