Honestly?
I think that that the excessive hand-wringing and research into the causes really just mask what we all already know. The longer 'debate' continues, the longer it will be before we confront the the fact that our modern lifestyle is at odds with the design of our bodies. Fifty years is simply no time at all to undo tens of thousands of years of genetic conditioning.
- We live high-stress existences. We may not have as many stress peaks as our ancestors did, but we have a more chronic, continuous problem.
- Inactivity is encouraged in millions of little ways. Both for our own convenience and simply because time demands on the individual have grown too great.
- We have solved the hunger problem (for now), but we have not solved the nutrition problem, which requires far, far more resources per person.
People who have turned to food due to a psychological problem are only a secondary issue. People have always had some mental issues, these are just manifesting themselves as obesity now, because food is one of the easier escapes, suffers no real social stigma (yes, an obese person is denigrated for being a 'glutton', but an otherwise healthy person eating a hamburger is pretty damned blameless) and is well and truly harmless in moderation.
it's far easier to tumble into a food addiction then a drug addiction and in some ways it's more difficult to stop (you can't exactly 'cold turkey quit' food).
The longer we talk about mental issues, the longer we ignore the fact that our societies are designed that we drive everywhere, live in a just-in-time culture, have no time to walk anywhere or spend time goofing off physically, that amateur sport has collapsed for the casual participant, that casual play has largely been discouraged among children, that our society and technology cater to the "vegetable in a chair" model of convenience, that... well shit...
Let me put it this way.
Look at the recent economic collapse. Now, there were a number of proximate causes of the collapse, but the REAL root issue is that we've spent decades fuelling growth with debt. You can always push the envelope to a degree, but at a cost. And if you continue to push farther and farther and farther, eventually you hit a point where nature snaps back, ripping up the whole damn thing.
It's a truism of nature that things are elastic - but only to a degree. The human body for instance, can go without sleep for a short while, or it can be chronically sleep deprived in small amounts over a long period, but there is a tolerance for both. It's not set in stone, and it can be highly variable from individual to individual, but it's there. Eventually you would suffer serious health problems, or just pass out.
In the same way, our current social construct has pushed and pushed and pushed. Productivity, that mantra of the businessworld has grown to unheard of leaps and bounds, mostly on the backs of people. Not so much because of increased mechanization or computerization (which I actually approve of!), but by squeezing more hours of the same employees, by moving to a world where both parents work instead of one, by 24/7 blackberry, by endless multitasking, by assigning more work to fewer employees and firing the ones who can't hack it. By the god-fucking-damned fool drive to quantify everything.
This world has no room for walking to work. This world has no tolerance for how long your commute is or what your personal problems are. It doesn't care that you don't have time or energy to do anything with your kids or that making a real dinner or eating something besides a donut-and-coffee for breakfast takes time. Don't give me that horseshit about companies with 'progressive' policies - they are few and far between.
Anyway, I generalize. There are good folks, and compies who 'get it'. And there are still plenty of individuals with a natural knack for using every last minute of their time in an efficient and useful way. There are towns that have tried to improve planning efforts and places where commuting and poor eating habits are discouraged socially (rather than institutionally).
But they are a minority (percentage being debatable).
Until we address the true costs of the way we've chosen to live our lives those costs will continue to have to be paid. If we wish to reduce our obesity levels, it will not happen unless we pay the cost in another way, by unwinding. No institutional program is going to help. It doesn't matter how many people get their stomachs stapled, or how many schools implement healthy lunch programs or force more gym classes. Until we change socially, obesity (and other issues besides) will continue to plague us.