You might want to just start by trying to cut out all simple carbs. I started by eliminating sugar and bread from my diet. I also started doing garlic. That may be enough to get you started until after the marathon and then do the strict diet after that. I don’t think that I had terrible die-off but then I think that my issues may have not been as bad. I did, however, have a couple of weeks where things were kind of tough. Good luck dear!