NYC has had a ban on serving transfats in restaurants for two years.
My understanding of the reasons for its use is that it's cheap, makes things taste good and probably most important to the food industry is it has a long shelf life. I don't know if what replaced it has all those attributes but if it doesn't then it's costing the consumer money. It may be helping some people live healthier lives but I don't eat many donuts myself or a lot of other things that may contain it so for me it doesn't do anything but drive the costs up. Even if the replacement does have all those attributes there is still the initial cost.
Frankly I'm getting tired of the "Nanny" mentality many of these politicians have, let the market make these decisions and leave it up to people. If trans fats are bad for you and someone can produce a donut that's just as good and just as cheap to produce donut makers will make them and people will seek them out. We don't need the government making that decision.
Getting back to the cigarette tax many will argue that cigarette smokers are putting an undo burden on others because of the health costs... the same is true of people that don't eat healthy, people that engage in risky behavior like mountain climbing or sky diving, people that drink a lot, people that don't wear their seatbelts etc.
The way things are going the government is going to tax and over regulate anything that can be deemed bad for you and won't be happy until we're all safely in a plastic bubble.