Glucomannan (konjac fiber)

Glucomannan is the name of a starchy fiber extracted from konjac root, an Asian plant. This fiber supplement is occasionally used as a thickener by the food industry. Glucomannan forms a thick gel which expands when exposed to water.

Two properties of glucomannan make this fiber a powerful weight loss aid. Glucomannan:

  • has no calories.
  • has the highest water-binding capacity of any known fiber.

Some studies have demonstrated that glucomannan taken as a supplement three times per day with a low calorie diet can lead to greater weight loss than with diet alone. In particular, this special fiber attracts water and swells in size while in the stomach, creating a sense of fullness. It also slows down stomach emptying. In this respect, it may control appetite.

Several studies have shown glucomannan supplements may also improve insulin sensitivity. Even improvements in cholesterol have been noticed with this supplement.

Diabetics who are on insulin or other medications are cautioned about the blood sugar-lowering effects of glucomannan. If you have diabetes, you need to work with your doctor to adjust medication doses appropriately. (Exercise and weight loss will also lower blood sugar and your medications doses may need to be adjusted.)

How can you find glucomannan? There are both food and supplement sources of this beneficial fiber.

Shirataki noodles made out of konjac root fiber can be found in some specialty food stores. We found them at Whole Foods. You can also obtain them from Amazon.com or konjacfoods.com although shipping can be expensive. These noodles have a tougher, more gel-like consistency than pasta made from wheat. Shirataki noodles can be used in place of conventional noodles but do not withstand cooking.

Glucomannan fiber can also be purchased and made into pasta at home. It can also be used as a thickener in sauces. Some individuals take the plain powder mixed in water before meals. It has a neutral taste.

Glucomannan capsules can be taken before or between meals to increase stomach fullness and decrease appetite. Capsules seem to be the safest and most convenient form of glucomannan.

Note that tablets (not capsules) of this starch have been found to be dangerous since they can swell in the esophagus before reaching the stomach. The capsule prevents this from happening, however.

A recommended dose of glucomannan is 1000 mg (1 gram) three times per day. Up to 3 gms at a time have been used in some research studies and appear to be safe. For best results, take about 1 hour prior to a meal. Drink at least 8 ounces of water with each dose. Avoid taking medications within 2 hours of glucomannan, since the fiber may inhibit their absorption. Do not take glucomannan tablets.

Some recommended sources

  • NSI Hoodia Glucomannan complex – take 1 tid before meals.

See www.konjacfoods.com for more information about glucomannan fiber and recipes to make your own pasta. They sell glucomannan powder as well as pastas.