From my experience of LEJOG & Chase the Sun, the periodic feeding of certain amounts of Carbs goes out the window after 2 or 3 hours, and the local cafes, corner shops etc offer all you need. Feed on what you want. To much of one thing for 13-15 hours will end up being a chore. You can’t beat normal food and an espresso to give you a pep for the next 3-4 hours