How is protecting citizens unable to protect themselves the creation of a nanny state? Right now there is a mom somewhere giving her kids a glass of pop with their Lucky Charms. Who's protecting the kid?
The best measure of any society is how it treats those least able to defend themselves.
Sure. The question is really how far are you willing to take it? When you take "protection from oneself" beyond the realm of real and present danger, it's all about someone else's interpretation of what is harmful and to what degree protection is required.
If there was scientific evidence that sexual activity presented a documented increased risk of heart attack for a man after a certain -- say, 40 -- or with certain health conditions -- do you think that the government has the authority to limit or prohibit him from sexual activity -- for his own good? What about for the medical costs borne by society for sexually related (preventable) heart attacks?
What about prohibiting that man from having sex for the purpose of prolonging his life -- in order to protect his child from the risk of losing his dad due to sexually induced heart attack?