Other areas of medicine could certainly be reduced more by healthy living.
This is a common misconception. Healthy living increases
lifetime healthcare costs. Fat smokers die young - their healthcare costs nothing once they're dead. Healthy people live to a ripe old age, nickel & diming their way to higher lifetime healthcare costs. Healthy living is great, but it absolutely won't save money.
But there's a larger problem that nationalized healthcare will fail to solve, because it doesn't address it at all: the system is already running at maximum capacity, and increasing that capacity (if it's done) will be staggeringly expensive, with decade-plus lead times.
Every healthcare debate focuses on funding ... who's going to pay for what, should fees be capped, should insurance companies be taken out of the loop by a single-payer system, etc. This is all rearranging deck chairs on the demand side of the Titanic, while water pours in through a giant gaping hole on the supply side.
The fact is, there simply aren't enough hospitals, clinics, and doctors in the United States for everybody to get everything they need. To illustrate this with a concrete real-world example, the demand for joint replacement surgery is obviously going to skyrocket as the Boomers get older, but we're not training orthopedic surgeons at a rate fast enough to keep up with that demand. And whatever Hillarycare or Obamacare or McCaincare plan gets passed, it won't magically produce more orthopedic surgeons.
Perhaps we could build more medical schools and subsidize tuition? That's tough; it's a huge project to open a new medical school - they need facilities, faculty, and should have an affiliated teaching hospital. But wait, where will all those new med school graduates do their internships and residencies? The residency programs in the United States are already full, and you can't just train a surgeon or internist or other specialist at podunk community hospital ...
The elephant in the room is this: hospitals aren't empty because people can't pay for health care - they're FULL RIGHT NOW. My hospital is no exception - every day, every operating room is in use continuously from 7 AM to 5-6 PM, Monday through Friday, with elective cases being scheduled for Saturday and Sunday too.
Moving around bits of green paper with dead presidents printed on them in the name of insurance reform won't magically create additional capacity in the system. If "free" for everyone nationalized healthcare becomes a reality, get used to the idea of long
waits for non-emergency services, and/or the reality of having your "health care provider" being a PA, nurse practitioner, or other midlevel instead of a doctor.