Glucomannan is a complex sugar and soluble fiber. The most commonly used type is konjac glucomannan, which is taken from the tubers of konjac, a plant native to Asia.
It is also extracted from [R]:
Eastern white pine
Higanbana
Lily
Orchid
Ramie
Redwood
Suisen
It absorbs water extremely well and has the highest viscosity of any known dietary fiber.
A few grams of glucomannan powder can turn a whole glass (eight ounces) of water into gel.
This fiber has been used in food for thickening and binding, as a fat substitution, and as a preservative.
It has gained in popularity as a dietary supplement, mainly due to its potential weight-reducing effects.
Mechanisms of Action
Glucomannan works by:
Taking up space in the stomach, making you feel full and eat less
Decreasing the amount of the hunger hormone ghrelin
Decreasing the absorption of nutrients (proteins, fats, and sugars)
Removing bile acids
Promoting the growth of good bacteria in the gut