Sure, junk food taxes just make sense too. Why should my tax dollars support every fatso and smoker out there? I'm ok with taxation in general but when people consciously make poor choices they should pay the burden. Unfortunately you're going to have a lot more trouble getting traction on restricting food than smoking. Maybe on a state level or something, I just don't see it happening federally.
Now you are getting socioeconomic. Shitty food is just plain cheaper than healthy food, the outcome of decades of subsidization of specific foodstuffs (cough, corn, cough).