The cheap unhealthy food certainly doesn't help, but I actually blame health insurance for the insane costs and lack of transparency in costs. You never know what something will cost until you get the bill and there's no way to shop around.
Insurance also causes a massive feedback loop. Insurance companies will only pay their share of costs if a procedure doesn't go a certain % over average price, so doctors raise their prices to the max insurance will pay... Raising the average which allows them to raise their prices again.
Of course this means insurance companies also have to raise their prices to be able to pay out what they pay.
The end result is a large family pays more in insurance than they do for their mortgage... And if you actually need to see a doctor you still have to pay insane amounts despite having insurance.
As mentioned above somewhere... If you need an ambulance, you will end up paying thousands for the ride, and that's after insurance has already cut the bill. Works great for doctors who take home several hundred thousand dollars a year. (All while complaining about how much medical school debt they have to pay and in hospitals the emergency departments always complain about how they have to see poor people who may not pay bills on time).
Insurance is the enemy. Costs too much to go to doctors without insurance but insurance acts as an unchecked inflator of prices and keeps forcing them ever upwards.