As we learn more about the addictive and destructive nature of drugs, "recreational drugs" becomes yet another term that is being refined. Precious few drugs are merely recreational - though I would grant you that marijuana is.
Yes, you are quite correct - it becomes very tricky when you deal with burdens upon society and try to have a free and unregulated society at the same time.
I am not in favor of restraining, regulating and taxing commerce; if I were though, I would say that every quarter pounder and Big Mac should come with a warning label like you see on a package of cigarettes - lol.
We as a society should do a better job of educating ourselves and our children of the importance of proper nutrition as well as the health implications of a bad diet. When we do, you will see the marketplace having an impact on fast food restaurants and junk food - just as you know see McDonalds and others adding healthier menu items and our public schools removing junk food and adding healthier menus.
I gotta tell ya, BNG, life ain't easy for a guy who wants to be a do-gooder but also wants maximum individual liberties and the government staying the heck out of our lives.