Yeah, Bloomberg was what I had in mind -- look at the backlash from that, even though it makes sense from an economic standpoint.
And yeah, there's consequences to any move like that. Banning cheap, shitty food raises food costs for poor people unless you're going to start providing them with low-costs alternatives (and convincing a trailer park family to eat quinoa and organic greens...good luck with that).
Plus the lobbying by the Shitty Food Associations (the Poultry Council would cry fowl), the Restaurant associations, etc. And then there's just the fact that *I* don't want to see fried chicken banned. Hell, I love a good fried chicken. I just also know that I need to cut back on it and that too much of it is a bad thing. Ultimately, personal responsibility is the only way to pull society out of the medical cost death spiral, but that's really tough to do without enforcing it in some way that makes it no longer personal responsibility. Smoking rates continue to go down, and while increased taxes are part of it, it's a lot of factors at work -- culturally it just doesn't have the "cool" factor that it did in earlier decades, the health risks are far better known, and the tobacco companies publicly acted like dicks and got hung out to dry for it. But this is another issues that correlates with education and income. Poor people and/or uneducated people are more likely to smoke, even though they're the strata that can least afford additional health costs.