I'm not preaching and I wouldn't pretend to tell anyone how to eat but I did find this article interesting as it does show a way to improved running performance and health.
An Article by CARL LEWIS
"Can a world-class athlete get enough protein from a vegetarian diet to compete? I've found that a person does not need protein from meat to be a successful athlete. In fact, my best year of track competition was the first year I ate a vegan diet. Moreover, by continuing to eat a vegan diet, my weight is under control, I like the way I look. (I know that sounds vain, but all of us want to like the way we look.) I enjoy eating more, and I feel great. Here's my story."