Ahhhh, yet another one of the heads of the modern capitalist hydra beast. You can't kill just one head, it has a hundred more, and another one will quickly grow back in its place. Hearing people discuss it, debate it and get angry about it is like watching someone play wack-a-mole, except they are beleagered by a hundred little goddamn moles all at once, and they can't possibly hit them all; it's hopeless and they can never win. You have to kill the WHOLE THING.
The cost of healthy food, huge annual government subsidies for mass produce farmers to compete with imported food, Monsanto, the way that GMO's are used to increase the corporate control of our foods, which of course has its consequences in Washington D.C. where big corporate interests of all stripes can successfully use their money to promote their interests and lobbying groups, (witness all of the lucrative American construction contracts awarded to friends of the Bush cabinet to reconstruct Iraq after it was brought to ruin during the course of the most recent war with them, for just one example), and then the entire corrupt banking system and how everything else reinforces it (and how everything reinforces everything else), and so on are all interrelated problems. You can't talk about any one of these issues in isolation from the rest. They are all mutually reinforcing at some level.
I wish I could give a better description of the holistic nature of these problems here, but it would take too long. But consider it as metaphor instead: If you want to fix a fundamentally unhealthy tree or bush, will cutting off individual branches solve anything? No, of course not, you have to attack the problem at the roots, or the trunk or something. If the fundamental problems are not fixed, the little problems will just keep springing back up, relentlessly until the fundamental problems are finally addressed.
We are at that point. My point being, if you want the western world (and especially America) to promote and support healthier dietary lifestyles you have to change a hell of a lot of other problems and relationships in the existing social organization of things to make that a permanent possibility. I don't think I myself can identify the root of everything, but I personally think campaign finance reform, in the united states, is one of the main legs at the bottom, one of the biggies. For reasons that take a lot to explain.
I like to try to take a big picture approach with politics and see what specialists in this or that specific social/political problem too often don't see. Not that I consider myself that good at it, but still.