Of course it's wrong that vast quantities of food is a wasted when some people don't have enough to eat. Restaurants and supermarkets who throw away perfectly good food past it's sell by date instead of donating it should be ashamed. And we should all try to use up the food we buy of we can. But some people are so far up on their high horse about food waste nowadays it's ridiculous
For example I was on a group holiday on half board and went out for lunch with a friend as well as her friend who I didn't know previously but who had come along on the holiday. I ordered a sandwich but could only eat about half of it and left the rest on my plate. The friend of a friend had taken a roll and some bacon from the breakfast buffet so hadn't ordered anything at the restaurant. She asked me if I was going to finish my food and when I said no she said she would have it because "food waste is wrong." She ate it, saving the bacon roll she had taken which she had for lunch the following day. She didn't offer to pay towards my sandwich or say thank you or anything. It was all done in a very judgemental way
When I talked to my friend about it she agreed with me that her friend had been rude but then added she didn't agree with food waste either. I asked her what I was meant to do and she said in future my friend and I could order one sandwich and share it. I was fine with this but sometimes would have liked to order something different from my friend, have something other than a sandwich, etc. But felt constrained to share because restaurants served such big portions.
AIBU and what do you do if you can't eat all the food you're served? If it's convenient for me I'll take the rest away to have later but that doesn't always work.