Dennis:
A. konjac grounded tubers have been used for a good number of years to lose weight. The powder absorbs a lot of water (you are supposed to drink a recommended quantity of water with the product or mix it with water before ingesting, this absolutely revolting as the resulting product is like a soft jelo) and will fill your stomach reducing appetite.
The tubers are edible and have been used as food in several Asian countries, reported to taste like chestnuts.