Abstract P182: Glycaemic Index and Glycaemic Load of East Asian foods: The INTERMAP Study

Background: According to recent national health surveys (2010-2013), diabetes mellitus (DM) is more prevalent in East Asian populations (11.6% in China, 11.3% in Japan) compared with Western populations (4.5% in UK and 8.3% in US), even though body weight and body mass index (BMI) are much lower in East Asian populations (mean ≈ 22-23 kg/m2 in China/Japan vs. ≈ 27-28 kg/m2 in UK/US, WHO 2008 report). Consumption of total available carbohydrate (CHO) (%kcal) in Eastern countries is higher than in Western countries. The patterns of CHO intake, dietary glycaemic Index (GI)/glycaemic Load (GL), may be important in accounting for these differences and their metabolic effects. Data on GI/GL of Asian foods are, however, limited. Objectives: To develop systematic methodology for assigning GI values to East Asian foods, and to identify East Asian foods contributing most to total GL, using data from the International Collaborative Study on Macro-/Micronutrients and Blood Pressure (INTERMAP). Methods: The INTERMAP Study is a cross-sectional epidemiologic investigation with standardized quality-controlled methods; it accrued four in-depth 24-hour dietary recalls, 2 timed 24-hour urine collections, 8 BP measurements and questionnaire data. National and International GI databases were used to develop a standardized algorithm for assigning GI values to the INTERMAP data on East Asian foods. “GL contribution of a food”, defined as the GI value of this food multiplied by total amount of available CHO contained in this food as consumed on average by all participants, was used to estimate total influence of each food on blood glucose, including absolute levels and relative percentages. Results: GI values of total of 2,928 East Asian individual food codes (2,030 Japanese food codes and 898 Chinese food codes) were assigned using this newly developed algorithm. Foods assigned with GI>0 using this algorithm contributed 92% (Japan) and 98% (China) of total CHO intake per day. Among Japanese foods, high GI foods were sweet red bean paste (Monaka, GI=91), rice cookie (GI=91), and rice cracker (GI=91). Among Chinese foods, high GI foods were flour and flour products (e.g., Mantou, steamed bread, fried dough sticks, and noodles, GI=88) and glutinous rice (GI=87). Foods contributing most to GL in Japan were white rice (54%), white bread (5%), sugar, syrup and preserves (3%); for Chinese foods: flour and flour products (25%), white rice (21%), and baked products (10%). Conclusion: With the algorithm we developed, it was feasible to assign GI values to East Asian foods. The composition of top GL contributors is different between China and Japan.