Ito konnyaku (糸蒟蒻) is a type of Japanese food consisting of konjac cut into noodle-like strips. It is usually sold in plastic bags with accompanying water. It is often used in sukiyaki and oden. The name literally means "thread-konjac." Konnyaku (Amorphophaiius konjac, K. Koch.) produced from tubers of konnyaku root, has been consumed as a part of important Japanese dishes for over 2,000 years. Science now unvail the real value of the konnyaku as a high dietary, non fat, fiber low calorie diet food which shows several unique functions for maintaining a well-being. Konnyaku is about as close to a zero-calorie food as you can get. No wonder, since it's about 97% water.
When taken with foods, it reduces speed of sugar intake which prevent rapid blood sugar level jump. Instead, it gives graduale increment. Study also indicates Konnyaku lowers Cholesterol level. Konnyaku is ideal for weight reduction since konnyaku forms jelly like material and expands about 30-50 times in the digestive system and gives the feeling that the stomach is full. The Konnyaku cleans the digestive tract of toxins. Most recently, the food industry is paying attention to the konnayku flour to replace conventional starch formulations since the konnyaku is lower in calories and lower in fat without sacrificing texture and taste.
Moreover, Konnyaku is one of the most effective items for defending yourself from fatness. If you would like to keep your body slim, it is necessary to keep the caloric intake in some amount. However it needs a great deal of patience if you decide to reduce your meal without any help. It may be also no good for your mental health to endure hunger. But if you use Konnyaku, you can eat ordinary or more amount of food every day because Konnyaku has very low CALORIE (3Kcal/100g). Since long time ago, Japan has such healthy foods like Konnyaku and Tofu. They will surely help your physical and mental health.
True konnyaku made from raw ground up konnyaku corms, called nama-konnyaku (raw konnyaku), is actually quite grey. Other types of konnyaku mostly seen just in Japan include sashimi konnyaku, which is konnyaku with various flavorful additives in it like powdered nori or citrus skin (mostly yuzu, but other citrus too), ito konnyaku, thick noodle-shaped konnyaku, and tama konnyaku, ball-shaped konnyaku. This Japanese page on a konnyaku manufacturer's site has pictures of these.
There is very little difference in flavor or texture between industrial white and grey konnyaku, so it's mostly a matter of aesthetics.
Konnyaku itself has very little flavor. It's the texture that will either be interesting or completely off-putting to the eater. It's gelatinous and firm, rather like agar-agar but firmer and rubbery. Since it has little flavor of its own, and because it's almost all water, it takes on the flavor of whatever it's cooked in.
Glucomannan has also been studied for treating obesity, diabetes, and high cholesterol. Studies in both adults and children with severe obesity showed varying degrees of weight loss associated either with taking supplemental glucomannan or with replacing some of the usual diet with foods made from glucomannan (konjac) flour--the dried and ground tuber (underground stem) of the plant. Generally, glucomannan is believed to discourage overeating because it creates a feeling of fullness because the fiber in it swells. Because stomach contents may stay in the stomach longer, the individual does not feel hungry as often. However, in most of the research studying glucomannan for weight loss, study participants also drank large amounts of water and followed a reduced-calorie diet.
Possibly due to the same delay in stomach emptying, glucomannan may improve blood sugar levels in individuals with diabetes. Because the absorption of carbohydrates from foods is slower when glucomannan is taken, blood sugar levels may not rise as high or as fast as usual. Some preliminary results from animal studies also suggest that glucomannan may increase the sensitivity of body tissues to the insulin that is produced or taken. In several studies, taking glucomannan has also appeared to lower blood levels of total cholesterol, low-density lipoproteins (LDL, or "bad" cholesterol), and triglycerides. Although more research on this possible use of glucomannan is needed, glucomannan may increase the elimination of cholesterol and its components from the body. It may also keep bile acids from being reabsorbed in the intestines, further reducing cholesterol levels in the blood, because the body uses cholesterol to produce more bile.