Glucomannan is a sugar made from the root of the konjac plant that has been used for centuries in traditional Japanese cooking as a thickener or gelling agent. It's so renowned in Japan that it even has it's own nickname--"the broom of the intestines" -- which gives you a pretty good idea of how it works. For just a few calories, glucomannan creates a sense of fullness by absorbing water and expanding to form a bulky fiber in your stomach.
"When consumed, glucomannan “sponges” up water in the digestive tract, reducing the absorption of carbs and cholesterol and thus supporting weight loss. [...] This supplement also makes you feel full without leaving you gassy or bloated," Dr. Oz explains.
The "bulky fiber" is then expelled from your body via the natural route. This cleansing effect has been said to help with a host of medical woes like reducing cholesterol, helping control blood sugar in people with type 2 diabetes, and constipation.
Does It Work?
While the research is still evolving and the FDA has not given its approval to any glucomannan product's health or weight loss claims, preliminary studies are promising. In one 2007 study published in the British Journal of Nutrition, participants taking a glucomannan and psyllium husk combination supplement lost approximately 10 pounds in 16 weeks compared to 1.7 pounds lost in the placebo group. Another study using only glucomannan showed an average of 5.5 pounds lost over eight weeks, without making any other diet or lifestyle changes.
How Do You Use It?
With no harsh chemicals, strange drugs, or additives, glucomannan powder (flour) and capsules are considered "likely safe" to use as an appetite suppressant. But there are a few side effects to watch out for. First and foremost, you need to be vigilant about drinking enough water. Dr. Oz advises drinking 8 ounces of water with 1 gram of glucomannan be