What about potato chips, fries, baked potatoes with sour cream, desserts, ice cream, etc etc etc?? This is rather arbitrary and specific.
Why not legislate grocery stores to be prohibited from selling them? Why not go all out and legislate that people have to exercise, and determine what their exercise regime will be, where they'll do it, and under whose supervision? And what about alcohol? That's rather fattening, too, and can have just as many side effects and health consequences.
Bottom line, though, instead of trying to control what people ingest through taxes, they should provide incentives for people not to, if they're all that concerned.