The food wasted after a party has passed through more hands than the guests will ever meet.

Food scraped into a bin at the end of a party has already been through a very long chain: growing, picking, packing, driving, stocking, selling. Dozens of people worked on it, none of whom are in the room, and the ease of throwing it away is a direct result of how far away all of that labour is.

This is not a case for guilt at the end of an evening. It is a case for planning at the beginning: buying slightly less, sending things home with people, having containers ready. Waste is mostly designed in at the shopping stage, and it is much easier to prevent there than to feel bad about later.