While I do think a company should be required to be honest about the unhealthiness of their products, similar to how tobacco corporations have to be very transparent about the dangers of cigarettes, I don't think overly taxing or banning any long-term harmful food product is going to stop anything, but rather generate new problems.
People want their vices, they want to satiate their cravings. No tax is going to break that addiction. Just try to educate people better. Raise the standards for healthy eating among society and let the free market decide. One thing people could try to work on is making healthy eating more affordable.