New York Times article, everyone on here should read.

This is really interesting - kind of covers a lot - why 3500 calories doesn't always equal a pound, why exercise is important for long term weight loss, why most people give up when plateaus happen (even if they don't mean to give up) - and plateaus happen on all diets - usually around 6 months or so...well, it covers a lot. Enjoy.

http://www.nytimes.com/2011/09/20/health/20brody.html?pagewanted=2&_r=1&emc=eta1