There is a huge cultural difference between almost every single payer nation and the US. For example, I haven't seen a regular doctor in 3 years for any kind of check up, because I'm uninsured. Meanwhile, I have friends in Canada that get quarterly or even monthly checkups. It isn't even a cost thing, they say it is cultural - their parents and peers expect them to regularly see a doctor to make sure nothing is wrong with them, and if they sneeze wrong they see the doctor.

I dislocated my knee this spring and reset it and just stayed in bed for 2 weeks. Never saw a medical professional, because they would want to x-ray (it might have broke, it was much more painful than a normal dislocation to me, and swelled huge for a while) and I'd be stuck with a $3 - 5k bill minimum just for that, combined with any treatment, and I'd laugh if they'd want me in physical therapy for it.

So it isn't just about not haivng a doctor to say 3 bic macs a day is bad for you, it is that in most other places people do see their doctors, regularly, and for most issues, beucase it doesn't bankrupt them. That adds up over a lifetime.