Background & objectives: Consumption of high glycaemic index (GI) food is associated with a high risk for diabetes. There is a felt need to understand the GI of common Indian traditional foods using standard GI protocols. The present study was aimed to analyse the carbohydrate profile of common traditional Indian food preparation and to determine their GI using standardized protocols.
Methods: Twelve food preparations made of millets, wheat, maize and pulses were evaluated for nutrient composition including detailed carbohydrate profiling and tested for GI in healthy volunteers using standard methodology. Capillary blood glucose responses for the test foods containing 50 g available carbohydrates were recorded and compared to the reference food (50 g glucose). GI was calculated from the incremental area under the curve (IUAC) for the test and reference foods.
Results: Available carbohydrate content of the food preparations ranged between 13.6 and 49.4 g per cent. Maize roti showed the highest total dietary fibre (7.5 g%). White chick pea 'sundal' showed highest resistant starch content (3.95 g%). Amongst the 12 test foods, five fell in the high GI category (finger millet balls, sorghum, pearl millet and maize roti), four in the medium GI category (sorghum idli, wheat dosa, methi roti and adai) and three in the low GI category (broken wheat upma, white peas sundal and white chick peas sundal).
Interpretation & conclusions: Merely being a whole grain-based food does not qualify for a lower GI. The method of processing, food structural integrity and preparation could influence the GI. The type and quality of fibre are important than the quantity of fibre alone. Judicious planning of accompaniments using low GI legumes may favourably modify the glycaemic response to high GI foods in a meal.
Keywords: Carbohydrates; diabetes; glycaemic index; millets; resistant starch; structural integrity; whole grains.