New edition lists more than 4,000 items, a 61% increase over the 2008 edition
Up-to-date, reliable glycemic index and glycemic load tables are critical for researching the relationship between health and the glycemic qualities of carbohydrates present in various foods and dietary patterns. Previous editions of the International Tables of Glycemic Index were published in 1995 (The American Journal of Clinical Nutrition), 2002 (The American Journal of Clinical Nutrition), and 2008 (Diabetes Care). Since publication of the last edition, the number of scientific publications that have included “glycemic index” in the title, abstract, or keywords has tripled. In response, The American Journal of Clinical Nutrition (AJCN) has published “International Tables of Glycemic Index and Glycemic Load Values 2021: A Systematic Review.” Researchers in nutrition, obesity, physiology, diabetes, and other related fields can now turn to this new edition for the latest vetted glycemic index and glycemic load values.
In this 2021 edition, authors Fiona S. Atkinson et al. have systematically tabulated both published and unpublished sources of reliable glycemic values of foods using a priori criteria developed by the International Standards Organization (ISO) to justify inclusion. The authors sought out new glycemic index values for foods. In addition, they looked for values that had changed over time as well as regional differences in values within certain food groups. Finally, the authors calculated glycemic load values based on standardized carbohydrate portions.
In order to develop the tables, the authors conducted a comprehensive search of MEDLINE, Cochrane Library, and EMBASE databases for relevant studies published between January 1, 2008 and June 30, 2020. The data were then divided into two tables based on data quality. Supplemental Table 1 contains the most reliable glycemic index values, with a full description of the food as well as cooking method, processing and composition, if available. Supplemental Table 2 includes glycemic index values for foods and beverages that were derived using methodology that did not meet ISO standards.
One of the key differences that distinguishes this 2021 edition from the 2008 edition of tables is the use of a standardized carbohydrate portion to calculate glycemic load values. In all, 21 standardized carbohydrate portions were assigned based on food category: for example, the standardized carbohydrate portion is 30 grams for bakery goods and 15 grams for legumes. This new approach eliminates the problem of calculating typical serving sizes, which may vary widely from product to product as well as from country to country.
In addition to the vast increase in published values, some new products entered the tables for the first time, including human milk; Chinese pearl barley; Asian fruits such as lychee, dragon fruit, and pomelo; and new varieties of dates, barley, and gluten-free products. Interestingly, whole tomatoes are a new addition to the tables, with a glycemic index of just 22, one of the lowest on record.
According to the authors, “the relevance of the glycemic index concept is confirmed by recent studies and meta-analyses linking it to the management and/or prevention of diabetes, weight loss maintenance, coronary heart disease, cardiovascular disease and mortality, and specific cancers. The authors do, however, acknowledge that more research is needed. In particular, they have noted that “more market surveillance and consumer-driven testing is needed so that it can be determined whether there are true regional differences in [the glycemic index of] staple products such as bread, rice, and potatoes.”
We invite you to peruse the tables yourself to search among the more than 4,000 food products now listed. The tables are freely available to all readers regardless of subscription status.