Seriously curious. If I consume somthing, don't I now posses it (it's in my body) or didn't I have to posses it for at least a moment (in order to consume it)

I'm just curious in what ways this distinction would play out. I can see if "consuming" was illegal and "possession" was not logically works but it's harder to see how "consuming" is legal and "possession" is not doesn't effectively make "consuming" also illegal.