Overview: Konnyaku is an important element of Japanese cuisine. It has long been known as a high-fiber, diet-friendly food, and in recent years it's been shown to offer benefits for health conditions including dementia and diabetes. Outside Japan, its popularity is on the rise, and it has started to appear in dishes like pasta. Konnyaku is a chewy, jelly-like food made from the extremely bitter corm of the konjac plant. How is it processed? And what other uses does it have? Peter Barakan visits Japan's top producing area to learn all about this surprising food.