I just think that people just don't understand all the weird crap that is in food today, and that we don't know enough about it to really understand what it does in our bodies.
Artificial sweeteners and preservatives aren't some scary bedtime story, we are finding that these foods are linked to health conditions like cancer, and as chad mentioned Alzheimer's.
And yes, a lot of the equation is that people don't exercise, that's true, we have grown so accustomed to sitting that in a few years babies will start being born with evolved extra appendage that looks like a swivel chair.
I do have to mention though my wife's school in taiwan, they went from monday to friday from 8am to about 9pm. They have such a stong education program there. Anyway, at her school, they didn't have recess, and they only had PE a couple years out of their whole k-12 experiance...enough lack of physical work that it would make a doughboy out of anybody. Oh, they are fed well too, and since their night school classes start about 45 minutes after their daytime classes, they have to drive over to the classroom, and pick up some fast food on the way. Daily.
They are still a country of stick people. I went over there, and they think I'm fat. I am only five pound over my recommended weight. They just eat natural foods. Their fast food is like a fresh soup and some fried egg.
I really have to say, I was not blaming food until I went to taiwan, changed my who perspective on what Americans eat. I started eating a lot more natural, preservative free foods, and I just feel better. (but of course, this isn't a replacement for exercise)
Ok, I made my point, take of it what you will, but I'm not going to really wanting to start a debate over it.
Have a good day everybody!