One aspect of the invention provides dietary fiber compositions comprising effectiveamounts of glucomannan, xanthan gum, and alginate to produce a desired viscosity.The invention also provides food products comprising an effective amount ofa dietary fiber composition. In other aspects, the invention provides methodsfor preparing a dietary fiber composition or a food product comprising a dietaryfiber composition, and methods for promoting satiety, promoting weight loss,lowering blood glucose levels, or lowering blood cholesterol levels in a mammal.