Disclosed are nutritional compositions having a solid crisp matrix, or a flour derived from the solid crisp matrix, said matrix comprising (A) from about 10% to about 50% by weight of a soluble viscous fiber, preferably guar; (B) from about 10% to about 99% by weight of a carbohydrate other than and in addition to the soluble viscous fiber; and (C) from about 1% to about 49% by weight of protein, wherein the matrix has a bulk density of less than about 0.4 g/cc. It has been found that soluble viscous fiber sources such as guar gum can be formulated into a solid crisp matrix, which then minimizes several limitations commonly associated with the formulation of such fiber sources into a conventional nutrition bar, e.g. slimy mouthfeel, tooth packing. These compositions are especially effective when formulated with gelled inclusions, including those containing or associated with acidulants, sour flavorants, or both. The nutritional compositions are especially useful as satiety agents, weight reduction agents, and/or for blunting the postprandial glycemic response in diabetics or other individuals in whom such a response would be beneficial.