Anyone who ate hot lunch had to eat everything on their tray, and we weren’t allowed to pass on any part of the meal because children in other countries were starving or something. Lunch ladies checked our trays before we were allowed to leave the cafeteria.
On the days when sauerkraut was served, we’d take turns being the sauerkraut smuggler, cramming that dank crap from about a dozen 8 year old kids’ trays into an empty milk carton, so we could toss it all without the lunch lady catching it. One day when I was the kraut smuggler, lunch nazi grabbed my carton and marched me back to the table. She said I had to eat every strand of the milky garbage we’d all stowed before I could leave.
I tried, but kept gagging and retching. I sat huddled with the collective slop at the table, crying for about 3 hours before my teacher found me and released me from lunch jail.
Supposedly there was a similar policy at my elementary school early on, which led to a kid being forced to eat something they were allergic to. As the story goes, they vomited violently all over the lunch monitor and then had to be taken to the nurse's office. Their parents were not amused. The policy did not stay in place.
We were quite lucky that our cafeteria had some delicious food for breakfast and lunch. I actually looked forward to it. Sometimes we'd get lucky and the lunch lady "overproduced" and would invite us to get seconds, and those of us who stuck around for them would get excited!