So... I went to one hospital with my mother. Very expensive, very nice hospital. 90% of the people there seemed to be about proportionate, didn't look overweight, and DEFINITELY none that were really big.
Went to the county hospital with a friend. Almost EVERYONE there was overweight, and a good number could probably be considered morbidly obese.\
Maybe.. I also think that a lot of poor people are working factory jobs, fast food, and jobs that are rather depressing. I would know lol. So a lot of times when you are unhappy in an aspect of your life you try to feel that void, and food makes a lot of people happy. Or for a moment it does anyways.
Processed junk is cheap. So is the dollar menu. Also, alot of people in the poorer demographics have never been taught to eat or shop for healthier foods. Its a vicious cycle, kinda like if you were raised on food stamps you will normally live that life as well. Some people break the cycle, some will forever live that way.