If you run 100 miles a week, you can eat anything you want - Why? Because (a) you'll burn all the calories you consume, (b) you deserve it, and (c) you'll be injured soon and back on a restricted diet anyway.
Don KardongNo doubt a brain and some shoes are essential for marathon success, although if it comes down to a choice, pick the shoes. More people finish marathons with no brains than with no shoes.
Don Kardong