Natto is a strange Japanese food that is made from cooked soybeans. These soybeans are fermented in a way that produces long sticky, strands of goo. Natto is good for you, but it is stinky and even the Japanese will admit that natto is an "acquired taste". Even so, a natto diet plan rose to fame in Japan.
The diet plan included eating two portions of natto a day, once before breakfast and once after dinner. The diet plan, they said, allowed people to lose weight with NO OTHER WORK. Sounds too good to be true, right?
Well, it turns out that it was too good to be true. The TV program that showcased the natto diet got into a lot of trouble for falsifying the data behind the natto diet study and had to publicly apologize for creating a story where there was none. Natto is a healthy food, but it isn't a magic potion.
If you want to try natto, you can find it at most Japanese markets. It is kind of sticky and yucky, but it is fairly inexpensive.