Consumption of herbal leafy porridges is a reputed dietary remedy among Sri Lankans in treating diabetes. The aim of the study was to develop a rice based herbal porridge [rice: fresh leaves: scraped coconut kernel 13 - 15: 25 - 30: 10 - 13 (w/w/w)] commercially with Scopariadulcis leaves which has proven antidiabetic effects and low GI (fresh porridge) which benefits diabetics. Two porridges with the same ingredient ratio were produced with different particle sizes. Porridge produced with 100% fine particles (extruded rice, leaves and scraped coconut mixed with rice powder) elicited a high GI for normal (92 ± 22) and diabetic (97 ± 20) subjects. The second porridge prepared with the minimum amount of extruded rice with other ingredients mixed with boiled and dried intact rice grains had a medium GI (normal 58 ± 11, diabetics 61 ± 11). A significant reduction (p < 0.05) in the peak blood glucose was observed in diabetic subjects for porridge 2 (12.4%) compared to porridge 1 (0.7%) when compared to glucose. The reason could be the significantly high (p<0.05) amount of larger particles (>0.5 mm) (63%) and minimum amount of extruded fine particles in porridge 2 compared to porridge 1 (1.3%).