You can eat what you want as long as you’re confident adjusting your insulin. However, if it’s your first Christmas with Type 1, then it pays to not go over the top, simply because it’s less stressful. So eat what you want but for things like Xmas pud, cake and mince pies just have a moderate portion rather than a huge amount. Better to have one mince pie on a number of occasions than 4 mince pies at once.