In some Catholic traditions, meat is not allowed to be consumed on Christmas Eve, but this can vary based on the country and region. In the United States, the Catholic Church allows for the consumption of fish on Christmas Eve, as long as it is not served with milk or butter. However, in countries such as Italy and Spain, meat is traditionally allowed to be eaten on Christmas Eve, with the meal typically consisting of seafood and pasta dishes. Ultimately, it's best to check with your local parish or church to find out the specific rules and guidelines for your area.