How to keep kids off lollies & cooked food?

Hello to everyone who've got kids of their own!

I'm interested in how you keep your raw kids off lollies/sweets and other unhealthy "treats" they get to see their friends and classmates munch on everywhere?

I don't know a lot about North American family culture but I guess parents are able to pack a living lunch for their kids for school. But how about when they go hang out at the mall full of "temptations" (particularly of the social kind), birthday parties? And when the kids turn into teenagers, all other kinds of occasions offering status and acceptance to those vulnerable minds via the means of cooked and highly unhealthy "food"?

How do you deal with that? Do you allow exeptions, do you stay strict, do you just watch and let them discover their own path no matter where it ends up?

I'm especially interested in the case of those families who live in the midst of non-raw fooders, not on some lovely private patch of land where fresh produce is readily available.
While I'm not exactly looking into starting a family in a long while but only searching options of living elsewhere than in the heart of a city, I'd still like to take into account some obvious obstacles on the way to a nature-oriented lifestyle for myself and those I might need to look after!

Thanks!

Jo