I work in a place that (I don't want to say offers, because it is the government that does the offering) oversees the free summer lunch program.
One of the rules is that no food can leave the cafeteria. Parents want to take leftovers home. They have to throw away the leftovers, so if the rules are followed the trashcans leave the building full of perfectly good food. Yes, your tax dollars are paying for that food rolling to the dumpsters.
Thankfully, I haven't been told to make anyone chunk their food. I wouldn't handle that very well.
It is incredibly wasteful. I'm sure there are people that would "abuse" the system, but I'm not the person to determine if someone is an abuser. I'm not sure what an "abuser" of the system would do to "abuse" the system. Maybe give food to someone who needed it?