Yes, because the food wouldn't be burned, and would sit there in my stomach until the 24 hours are over. I'd feel full, but I'd essentially be fasting. This would also limit how much water I could drink, so I'd be wise to leave room for water. In fact, there'd be no point in eating anything, except to store it for when digestion starts up again. The genie's probably trying to trick me into overeating and suffering from thirst, and having extra calories to burn after 24 hours, made up of fattier, saltier, sugarier foods than I would have had.