Until recently, the U.S. government required a noodle to contain flour, water, and eggs. Most Asian noodles do not contain eggs, and so they did not fit this FDA definition of a noodle. The agency permitted names like alimentary paste or imitation noodle but would not allow Asian noodle producers to call their product noodle in America. It had to be called something like pasta instead. But the regulations finally changed, and we can now call a noodle a noodle. Koyo Soba, Udon, and Somen pasta are, in fact, noodles.