In many countries it's tradition to eat good-luck foods in the first few days of the new year or sometimes in the last few seconds of the old one. People in Spain stuff their mouths with grapes as the clock counts down the last twelve seconds. In the United States, Southerners eat collards and black-eyed peas because they symbolize money. My Hungarian heritage is not without its new year's food superstitions.
To celebrate, we eat pork and lentil soup. Supposedly because pigs root forward, they are a forward-looking bunch of animals. Chickens are not since they scratch backward. We eat lentil soup because the little lentils resemble coins. So the custom of eating good-luck foods is all to gain prosperity for the new year. Believe me I'd eat all these foods all the time if it meant prosperity for the entire year.