There is described a process for preparing a food or beverage composition having sweetness and a low glycemic index that entails incorporating in the composition a low glycemic index product comprising sucrose and an acceptor selected from the group consisting of a sugar and a sugar alcohol having free hydroxyl groups at one or more of carbon positions numbers 2, 3 and 6 that can accept a glucose unit from sucrose, the blend having been reacted with a glucansucrase enzyme. Also disclosed is a process for reducing glycemic index of a food or beverage composition that entails introducing into the food or beverage composition a low glycemic index product comprising a blend of sucrose and a syrup or syrup solids comprising an acceptor selected from the group consisting of a sugar and a sugar alcohol having a free hydroxyl groups at one or more of carbon positions numbers 2, 3 and 6 that can accept a glucose unit from sucrose, the blend having been reacted with a glucansucrase enzyme.