I shared my opinion on FB:
Agreed with most opinions above. There is not much you can control but continue to expose, cultivate to children. They will request to "design" their lunch boxes as they matured. Continue to instill that healthy eating mindset to children, never give up.
As for parents, try to:
1) create a healthy lunchbox competition or easy healthy lunchbox, once a month (maybe parents will showcase their knowledge!)
2) "report card" of daily lunch boxes - 1-2-3 healthy stars and tabulate weekly and crown the child.
3) wrappers > recycle as bookmarks and send home.
Tab on child to motivate parents.
In Singapore, we don't practise lunch boxes but snack boxes: