They just need to be more rational than the general population. Usually politicians don't really decide things though, but they're putting the stuff experts tell them into laws and arbiter between interests.

You'll need governments deciding things anyway. Otherwise you can't come up with fair contracts when there's a difference of power in the parties of the contract (think e.g. costumer and manufacturer and food safety regulations), even when both sides are rational.

> You're free to choose unhealthy products, but aren't forced to choose them

It's not that simple. For instance, kids aren't free to choose what they eat or drink and they can't make rationale decisions. Many adults lack the proper information and so on...

I don't think promoting your lifestyle to others is something that has any force, even if any of us were interested in evangelism. People pick up their everyday behaviour largely from what they perceive as normal, and mass media, which is filled with adverts and even the programming heavily decided by commercial factors, has enormous power to dictate what is normal. At the grass-roots, parents have a degree of power to set a concept of normality for their kids, but that's also strongly driven by peer-pressure which is in turn driven by mass media.

>No it don't. You're free to choose unhealthy products, but aren't forced to choose them.

Forced for humans is not just "gun in the head", and it's not a binary either.

E.g. constant hammering with advertising on TV and internet can be an effective force for forcing people into stuff they wouldn't otherwise do.