All of the food in the main dining room, the Lido restaurant, the pizzeria, and room service is included in the price of the cruise. A couple of the newer ships have little specialty restaurants that charge a little extra, but not Jubilee.
Not only is the food free, it's plentiful. Can't decide between two different main courses - ask your waiter to bring both. And don't forget the midnight buffets. You won't go away hungry.
3 days 'til Victory
PS - Be sure to take some looser clothing for the end of the week. You won't be able to fit in your normal clothes by then.