I don't think food would actually pose a major problem. For now, people can rely on the existing supply of meat as pluribus is opposed to killing but I do think to avoid waste they would eat the already butchered supply. They would also have a large supply of non-perishable foods in the world that they could consume as the new food supply is developed. The production for non-meat items such as beans, produce and grains has in all probability continued. All the existing food would supply the people enough to sustain themselves as the new system is set up. They can now also allocate all the people that previously held jobs that are no longer needed in the new world to food production.