Actually, however, the government uses the fact that it already pays for at least some health care (medicare, medicaid, subsidized insurance) as their rationalization for why it can control our actions even if they don't affect others.

In fact, that's how they justify making us wear seatbels. Being one of the old farts here, I remember when the government mandated seat belt use in the early 80s. They said that they had the right to do so because people who were injured often ended up, if injured severly enough, on public assistance. Therefore, they had the power to tell us what to do with our own bodies (if you will).

I also remember that some of the more libertarian elements of the country argued "if we let them get away with THAT argument, next they rationalize banning smoking, then drinking, then fatty foods, then..." And the do-gooders said "no, no...they'd never do that.."

So if you have a federal government that pays for everyone's health care you can guarantee that you'll have a federal government that tries to assert more and more control over our lives over time, on the theory that they have a right and duty to cut costs by mandating we only engage in "healthy" activities.