You guys are full of it.
American fast food contains the four food groups(cheese=milk, bun=carbs, "meat"=protein, ketchup=vegetable).
The high fat content is part of an Atkins diet(who incidentaly died young of heart disease), and a link to obesity has never been definitivly proven, just as there has never been a definitive link between cigarettes and cancer. There are always other factors involved.
Besides, fast-food has many decades of traditional history and is integral to every cultural community.
Just see for yourself:
http://i-am-asian.com