The Federal government has no legitimate role in healthcare, other than for the Armed Forces and Veterans.
But Democrats long ago cast off the constraints of Article I and the Tenth Amendment, realizing that they can essentially buy votes with "free" government services and stuff. Every vicissitude that life might throw at us can be alleviated or resolved by Government, if only Republicans weren't standing in the way.
So the Feds created agencies to regulate food, drugs, and various human activities, and took it upon itself to advise us what to eat, what to do, and what we should not eat or do.
I don't think many people endanger their health UNWITTINGLY; we do it on purpose, because instant gratification is more satisfying than long-term sacrifice for good health.
Sadly, many of us suffer from horrible diseases, circumstances, and conditions despite "doing everything right." You can eat right, watch your weight, exercise regularly, and avoid harmful stuff, and still suffer and die early.
Fortunately for me, at 76 y.o., it is no longer possible for me to die prematurely. I'm well past my sell-by date.