Well, they tax tobacco, which by now is banned all over the place and second hand smoke complaints are not the norm. So that's a tax on personal choice right there. If health spendings due to obesity are nearing those due to smoking, there isn't much of a difference in taxing, at least as far as this justification goes.
Of course one could still pass second hand smoke to family etc living together, but then again they can also feed them chocolate and coke.
I'd be fine with both C and D tax options! (And not extremely fine with heavily taxing selected food venues, because it's perfectly easy to bloat on supermarket shopping). Yeah, there are going to be some fat people who won't necessarily require those medical costs. Well, it's the same for smokers, shorter life cuts a lot of spending on meds and care, but some live long and might need more. It's just a risk profile, any type of insurance, state or private, is about pooled risk.
