I wonder whether kids diets have just got worse over the years. I seem to know a huge number of kids who are really picky- even to the point where a meal I ran past their mum (chicken nuggets and chips, so not even anything healthy) was rejected because I'd clearly bought the wrong brands and it wasn't edible.
An awful lot of parents seem to make packed lunches because their kids are too fussy for the school dinners. Mine have school dinners- because a) learning to eat what's on offer is a useful life skill and b) vegetable eating is far more likely when presented with a cooked meal than in a packed lunch and c) they're free!!
When asked during a class discussion on healthy eating recently, my child was the only one in the class who had a healthy snack (fruit). Everyone else had crisps/chocolate type stuff. It had the opposite effect than the teacher intended as mine came home declaring me the worst parent of all for the poor snacks I provide 🤣
If what I'm seeing around me is the norm, with processed food being so cheap and so easy to feed them (fewer "eat your greens" arguments too), it's maybe not a surprise that nutrition is getting worse?
I can't imagine children in areas like the Mediterranean (as a neighbourly example) getting away with what kids round my way do!!