The fat controls them more.  It was once thought that fat cells just lied dormant not doing much to the body.  It is no believed that they help control one's appetite.  So the more fat cells you accumulate the more hunger signals that get sent out.

Here is the link that I was referring to.

http://www.huffingtonpost.com/stephen-barrie-nd/your-fat-cells-control-yo_b_732201.html

You are right about leptin controlling hunger but this is the part that I was trying to point out..

"In recent studies, evidence has shown that fat tissue -- far from being a dormant storage depot for surplus calories -- is actually an active organ that sends chemical signals to other parts of the body with profound and sometimes harmful effects to your body. Fat seems to have an infinite capacity to make more of itself."

Not really much of a point but I was trying to state that they multiply easier the more you have or something like that.  The more fat you have the easier it is to accumulate even more.

Another good quote from the article.

"While we are still in the early stages of research, new discoveries and findings make an even more compelling argument for controlling those billions of fat cells in your body. As Gokhan S. Hotamisligil, a professor of genetics and metabolism at the Harvard School of Public Health says, "Many people think your brain controls your fat. We promote the idea that your fat controls your brain."

This assumes there is a prime mover other than economic conditions, as well as assuming that social mobility is much easier than it actually is (although to be fair, social mobility downward is pretty damn easy)

That would be unfair market advantage similar to subsidy.

Unfair market advantage for healthy foods such as fruits and veggies?  So be it.  The way I see it healthy food is already at a disadvantage against junk food since high fat foods are easily picked over healthier foods.  Would you rather them continue to be fat (on tax payer money) without making any changes in their food intake thus raising the cost of health care even further.  The more fat USA population gets the more expensive.  Healthy people are far cheaper to maintain than obese people taking 20 different medications for their obesity related issues (when they could just drop the weight and not take any bullshit prescription pills).

I don't really care about how much the entire food stamp program costs.  For one to become or stay fat while collecting food stamps (spending money that you didn't earn) isn't right.  If you want to buy junk food with your own money then so be it.  I believe if you are collecting hand outs then the government should be able to tell you that you can't have junk food anymore, and if they are morbidly obese then they should be forced to lose 5-10% of their fat every few months (if collecting food stamps).

There are definitely variables, and some people may well sink as economic conditions worsen or the economy changes in a way for which they are unprepared, but it's usually temporary. Even in tumultuous economic times it's self motivated people who will tend to find a way to adapt to a new economy after they've been thrown for a loop while the less motivated tend to just stay at the bottom even after the economy improves. I'm not saying that if someone is poor right now they must be lazy. Similarly, someone needn't be obese just because they're poor. But the trend is clearly there, and a general lack of desire for self improvement is the only thing that makes sense to me. I'm surprised that it's even a controversial point, to be honest, and I'd be outright astonished if anyone would suggest that people have similar levels of self motivation regardless of economic status. I'm aware there are exacerbating factors, like those HappySqurriel referenced, and I'm totally open to another explanation as long so it doesn't rely on falsehoods like, "It's more expensive to eat healthy!" It isn't, and anyone who's ever set foot in a grocery store or even glanced at a supermarket circular should know better.

If you're talking about free citizens, that would be one thing. It is not quite so unreasonable to treat people who choose to live like wards of the state as if they are in fact wards of the state.

I'd say it's not an issue of expense, but of effort and education, for this extends not merely into how the poor are less likely to be healthy, but are less likely to vote or participate in civil society organizations (that is to say, participate in an organization independent of the government or their job, keeping the argument open that merely going to church doesn't count as participation). I recently completed an 80+ page paper on democratization, and my findings indicated as well as the research i cited indicates that the greater your economic hardship is, the less likely you are to be able to dispose of your free time in anything, i'll have to say, productive (whether that is getting in shape or pushing for political reform in your community)

Part of it is cultural, of course. Those who are born poor may enter into a culture of poverty that places less emphasis on self-betterment, but i still move that the lack of motivation is environmental and generally not due to the decisions of the individual.

The expense of eating healthy is indeed overstated (unless we want to say that organic only is eating healthy, and even then organic alternatives are not that prohibitive), but the effort that it takes to compile base ingredients into a meal when the roughly-equal-cost bucket of chicken is available at KFC, and available right now, is more daunting.

I'll note that it happened to my cousin, too. She finally got a job in April 2010, and i noted by Thanksgiving of that year that she had rather let herself go, which was likely because of the drastic loss of free time that comes with full-time employment compared to the 9-months of post-graduation job-hunting that she did. The pressures of time are a real factor for the working poor.

lol I knew you were going to take it that far.  I am not for government controls.  However, if someone is taking money from the government then the government should be able to control how that money is spent.  I stated clearly that anyone can get fat on their own money.  They just have to do a separate transaction at the counter.  One for the food stamp card accepted items and then cash or credit for their junk food and cola.