Carbs are certainly the most important thing to a runner....
But that said, I have to say that one shouldn't skimp on the
protein either.
It helps to repair the muscles after a long and hard run.
Microtears and miniscule damages in the muscles can build up if
you're taking on a long and serious training schedule.
Take note though when I said long and serious
training schedule. 
I think maybe with Fatum, you need to drill it down further.
What's definition of "long" and "serious"? Number of days? Number
of hours? Intensity?
