Children may not get a choice in whats on their plate, but they do have a choice in what goes in their mouth. Schools cannot force a child to consume anything, and the kids are free to toss all the food given to them into the trash, and they do, but not totally, some of that food appears in places other than the trash.
Kids, who as a category have no income, have a Hobson's Choice: eat or go hungry.
The UK also has (or recently had, I no longer follow news from there) a significant poverty rate such that lunch was some school kids' first meal of the day, and free school meals was a significant political issue.
Kids, who as a category have no income, have a Hobson's Choice: eat or go hungry.
The problem is that if kids don't eat lunch and go hungry that will negatively affect their ability to learn. As such offering less healthy food that they actually eat might very well be better than healthy food that they don't eat.
This is a problem for society, it doesn't enter the minds of the kids.
If the only meal is literal dog food, hungry kids will eat it direct from the container — a fact I know thanks to a real-life experience of an ex-girlfriend who was trying to be helpful and charitable but had a fit of middle-class naïveté after finding a puppy in a school in Kawangware.
