As you may have suspected, the macaroni in the song "Yankee Doodle" is not the familiar food. The feather in Yankee Doodle's cap apparently makes him a macaroni in the now rare "fop" or "dandy" sense. The sense appears to have originated with a club established in London by a group of young, well-traveled Englishmen in the 1760s. The founders prided themselves on their appearance, sense of style, and manners, and they chose the name Macaroni Club to indicate their worldliness. Because macaroni was, at the time, a new and rather exotic food in England, the name was meant to demonstrate how stylish the club's members were. The members were themselves called macaronis, and eventually macaroni became synonymous with dandy and fop.