Hi Kalli and fetish,
not all of the waste a human body produces is necessarily unhealthy. Provided the person is healthy, there's no risk in drinking piss. In fact it's almost spetical(? is this the right expression for a fluid without any bacterias and things?).
I'm not so sure about shit. There are some more things involved there and it's not so clean. So there is a risk eating that.
But surely, as long as the "delivering" person is healthy, it`s not a big risk.