We had fast food delivered to our Youth Center (basically an alternative cafeteria on campus for students) at my H.S. (and had been for the LONGEST time) and that was WAY back in 1997-2000.
So this is
not a "new" phenomenon by any means.
Here's something else interesting that people are already alluding to in here with P.E. (or lack thereof). Do some research on the correlation between the current real issues with early childhood education and lack of recess time in elementary schools. Bottom line: screw fast food, I think
that's where the correlation for obesity should be drawn as well.