I remember hearing a few anecdotes about abstaining for food for a period of time (fasting) and improved brain performance. I also seem to recall some pop-sci explanation involving detoxification of the body and the like. Today something triggered interest in this topic again, but a quick Google search did not return much on the topic (fasting is drowned in religious references).

I figure this is well within LW scope, so does anyone have any knowledge or links that offer more concrete insight into (or rebuttal of) this notion?