The present invention relates generally to a method of blunting the postprandial glycemic response to a meal by feeding an acid controlled induced viscosity fiber system. The first component of the induced viscosity fiber system is anionic soluble fiber. The second component of the induced viscosity fiber system is water-insoluble, acid-soluble multivalent cations. The fiber system will typically be incorporated into a meal replacement nutritional.The present invention also refers to a method of delivering soluble fiber to diabetics and to persons needing to lose weight. Additionally, the invention refers to a method of promoting the feeling of fullness and satiety by feeding a nutritional product containing the induced viscosity fiber system.