Nothing seemed to work the way he thought it would. Then one day the group was engaged in a discussion of possessions, and the conversation turned to the difference between wants and needs. On the next trip, the leader reminded the young people of that conversation. Then she suggested that at lunch that day each person was free to order whatever they needed. But, she said, everything you order you must either eat or share with someone else.
Nothing is to be thrown away or wasted.
He left it at that. You know, I bet we could really get by with a lot less than we think we need. From then on, the group monitored itself. As new people joined, one of the young people would explain the system and how important it had become to the group. As a side effect, parents began to notice different patterns of consumption at home.