Any "sharing" is a choice. Why are they obligated to make that choice less expensive? If you don't like their expenses, don't pay them. And, don't take their money.
> But I care about obesity being a drain on society
Surely you're not arguing that people "owe" society full-productivity or somesuch?
They prefer food. If that's a problem for you, perhaps you should wonder why food is more important to them than the things you want them to value.
Any "sharing" is a choice. Why are they obligated to make that choice less expensive? If you don't like their expenses, don't pay them. And, don't take their money.
> But I care about obesity being a drain on society
Surely you're not arguing that people "owe" society full-productivity or somesuch?
They prefer food. If that's a problem for you, perhaps you should wonder why food is more important to them than the things you want them to value.