You mean you had a choice?? - when I was at school (mind you this was in teh 50's and 60's) you ate what you were given. If you didnt like it there were usually two outcomes - depending on the teacher on 'lunch duty' :
1. You left your food and went hungry
2. You left your food but was then given a reprimand/clip round the ear for being so ungrateful - especially when there were 'so many starving children elswhere in the world'
I certainly remember at junior school the headmaster taking the last option - woe betide any kid who left any food on his plate - depending on his mood you would either get a fairly stiff telling off but kept qiuet-ish....or... if he was in a bad mood - the whole school would know how ungrateful you were because of the 'starving kids etc etc'
Many was the time I ate some food (cannot remember what it was now) with my nose pinched between my nose like some foul medicine
with reference to the above,
even though i had a note from my mother stating that i was allergic to liver, i was given instead, mash and cabbage with .........the gravy from the liver!