It's not uncommon to have names - often disparaging - for people based on their eating habits. As well as calling Germans 'krauts', as Shaney explains, we call the French 'frogs' because they eat that creature's legs and Liverpudlians 'scousers' because sailors from that port were often fed on a dish called 'lobscouse'. Of course, in retaliation, the French call Brits 'rosbifs' based on our habit of eating roast beef.