The invention provides a method for reducing the glycemic index of a food product, the method comprising adding to the food product prior to consumption a composition comprising a dietary fiber blend in an amount effective to reduce the glycemic index of the food product by at least 5 glycemic index units, wherein the fiber blend comprises from about 48% to about 90% (w/w) glucomannan, from about 5% to about 20% (w/w) xanthan gum, and from about 5% to about 30% (w/w) alginate.
