Good New York Times article on BigPharma out of control. It mentions obesity as one of the conditions whose definition has been expanded over the years.
http://www.nytimes.com/2007/01/02/health/02essa.html?_r=1&ref=health&oref=slogin
http://www.nytimes.com/2007/01/02/health/02essa.html?_r=1&ref=health&oref=slogin