Substances lead to poor health when they are abused. Cigarrettes, cigars, pipe tobacco, alcohol, etc. have no serious health risks when used in moderation. Soft drinks, hamburgers, fries have serious health risks when abused. The government should not tax on the assumption that one will abuse one substance and not the other (I know plenty of people that eat McDonald's on a daily basis, yet have a cigarrette only in a social environment, about once every week or two.)
The bottom line is, the government needs to stop providing free health care. Charities can step in and do a better job than government in caring for the poor and sick, yet many do not donate as much to charity as they otherwise would because they are already forfeiting 40% of their income to government social programs.