RE: Running Diet?
from experience (regularly race any distance between 10k and marathon) carbs are the way forward. to be honest carbs are the only really effective way of fueling yourself for running.
what exactly are you doing in your running sessions ?
get the running sessions right and you could probably get away with 3 runs a week instead of 4 for the GNR. also getting the runs right you won't have to change your diet as much