Solid dietary supplement comprises a dietary fiber composition comprising a quantity of at least insoluble dietary fibers consisting of celluloses, hemicellulose and lignin and a quantity of at least water-soluble dietary fibers that are resistant to human amylases and have a solubility in water of greater than 10 g/l at 20[deg] C, where the water content is 10-35 mass%. The solid dietary supplement is in the form of flexible sheet having a thickness of 1-5 mm and is adapted to be inserted between two slices of bread for a sandwich. An independent claim is included for preparing the solid dietary supplement comprising selecting the dietary fiber composition, mixing the dietary fiber composition and suitable amount of water in a kneader to be able to form a non-flowing solid paste, molding the non-flowing solid paste by extrusion to form a dough piece having a thickness of 1-5 mm, thermal treating the dough piece at a core temperature of 75-85[deg] C for 1 minutes to 10 minutes to obtain solid dietary supplement. ACTIVITY : Hemostatic； Antilipemic； Antidiabetic； Anorectic； Cytostatic； Anabolic. MECHANISM OF ACTION : None given.
