I found this fascinating quote today:
"Reduced sleep duration has become a common aspect of the westernised lifestyle, defined by physical inactivity and overeating," Dr. Plamen Penev, from the University of Chicago, told Reuters Health. "Diet-induced weight loss is a major behavioral strategy for metabolic risk reduction. However, whether it is effective during times of reduced sleep duration is unknown.Laynie - The Marketing Muscle, MarketingMuscle in Oz, Oct 2009
You should read the whole article.