In my country the media including the tabloids are constantly discussing healthy eating. I was taught at school about sugar being bad for you, shown the "tooth in a glass of Coke" thing.
We had cookery classes teaching us healthy things to cook too.
Things like lentil soup, coleslaw, quiche, homemade pizza, bolognaise sauce, apple pie etc. We did drink brightly coloured ice drinks and sweets on the way to school. (There was an amazing sweet shop at the top of my road, it was very popular before and after school.) But for most people didn't have mircowaves and us kids were still feed our meat and two veg dinners. And we were not fat.
The difference is the our kids are often not taught cookery any more. (If they don't recognise a courgette/zuchini!!) But their parents were taught and feed better, so they should now better too.
Advertising is more and more aggressive, in the UK MacDonalds advertises directly to tweenage kids (8-12), they put in a comment in it about making sure the exercise and run about, but it is encouraging kids that are out in groups to eat junk.
I understand the poverty issue but fresh food is cheaper than meals from the chill cabinate. And if you bulk buy you can make spaggetti sauces, cassoroles, chilli etc and freeze it. They way you only have to buy the veggies, it is a mircowave meal but with nothing nasty in it.