Ah, school lunch follies.
Went to a Catholic school for grades 1-8. Didn't have a cafeteria, so everyone brown bagged their lunches. Nuns and lay teachers for the most part didn't care what we had, but in 5th grade the teacher was always complaining that I had a thermos with hot soup in winter; she somehow felt that I (and a few other students) shouldn't have it because not everyone had it.
We politely heard her out . . . and ignored her wishes. Any attempt to take
food from a student would have ended badly.
In 8th grade teachers would sometimes pick a kid and give him some money to go across the street to a restaurant and buy them a carry-out lunch. I was the first kid who not only did that, but used his own money (NOT the teacher's!) to buy himself a good lunch as well, on a separate check.
One teacher didn't like that, and demanded I hand over what I'd bought myself. I refused and walked away from him, fully expecting him to grab me by the shoulder and try to forcibly TAKE it away from me - I figured I'd be able to punch him right in the nose when that happened, after which all hell would break loose. But I'd get that one good punch in.
But he never laid a finger on me. Much later, I figured out that in the aftermath it would have necessarily come out that he was sending elementary students off campus to run errands during the school day, which of course would have been a career-limiting move for him.
My high school cafeteria had both a "fast food" and "healthy meal" line. Only once or twice during my 4 years there did the lunch ladies try to insist students get a "healthy meal" (and pay for it!) but I don't think anybody
ever complied. And of course with high school being an "open" campus, we were free to go about a block down to fast food row and get something else.