Eh, banning a "food" probably isn't a good direction to go. Banning cigs in certain places is justified because it infringes on others rights to not have to breathe your smoke. But banning food? Basically they're forcing you to be more healthy.

IMO laws should only be enacted when your actions infringe on others rights. Eating trans-fat foods doesn't infringe on anyone elses rights. But remember, this is California. Chances are they'll seceed from the Union in the next 50 years or so and form their own socialist state.