The main reason poor people tend to suffer from obesity is because it's much more expensive to buy organic vegetables than it is to buy some McDonald's. (Organic food stores don't even tend to open in poor neighborhoods.) Running around in circles burns very few additional calories; certainly not enough to deal with this fact.
A meal at McDonald's winds up costing, what, six or seven bucks? That's quite a lot by home-cooking standards. You can easily put together a nutritious meal at home for that kind of money (grilled chicken + rice + fresh vegetables, frinstance). Don't get me started on the alleged nutritional benefits of so-called "organic" vegetables over the cheap-ass vegetables you can buy at my local ghetto Safeway.
Poor people are fat for the same reason they're poor: they have a lack of self-control and are not very good at making decisions.
Or if that sounds cruel, an alternative formulation: some people lack self-control and aren't very good at making decisions, and they tend to wind up being both fat and poor.
If the poor are obese, they are already spending more on food than they need to be. They could simply purchase fewer big macs, right?
But I really don't buy this theory. If it were true, it would imply that graduate students should be fat too (which they usually are not). The fact is, big macs are cheaper than most other foods per calorie. They are not cheaper per meal.
Incidentally, Harlem has plenty of produce (organic and non). But (based on my anecdotal observations) it's mainly purchased by the yuppies.
Humans need calories, it's true, but more than that we need nutrients. McDonald's food is carefully processed and stripped of its natural nutrients, so that you need to eat much more of it to get the nutrients you need. It's also packed full of calories, so that it tastes good, so eating enough of it not to be malnourished requires eating a lot of calories as well.
