Glucomannan, also called propolene, not to be confused with propylene, is a polysaccharide and mainly a straight chain polymer. It is widely used as a food additive, E number E425, with thickening and emulsifying characteristics. Glucomannan comprises almost half of the corm of the amorphophallus konjac plant, the so called “devil’s tongue” plant, native to warmer subtropical to tropical eastern Asia. Some studies have shown that this dietary fiber may hold multiple health benefits. It has been and currently is in clinical trials for treatment of constipation, obesity, cholesterol and type 2 diabetes. For weight control purposes, it has been observed that glucomannan promotes satiety when ingested, significantly reducing food cravings. It was also observed that when used with chitosan, glucomannan seemed to decrease serum cholesterol.

Konjac Root, a water-soluble dietary fiber, fiber may be helpful to those trying to lose weight because it absorbs water and provides a feeling of fullness. Konjac is commonly used in traditional Asian foods such as noodles and tofu.