I just watched the documentary "Super size me" about the guy who lived on McDonalds alone for a month.
Frightening stuff indeed, although he admited it was extreme, some people visit McDonalds daily, or perhaps three times a week is not unusual.
Toward the middle of his task Doctors were concerned at the damage the diet was doing to his body.He was having headaches, waking up breathless, but get a rush after eating, just like a junkie.His body wieght increased as did his cholesterol and his body fat levels,Kidneys suffered too.
Follow the link
http://www.supersizeme.com/ http://en.wikipedia.org/wiki/Super_Size_Me
Must admit I like the occassional Big Mac......against best information available now though.