We know we live in a closed energetical environment.
Upon living from Prana, that would mean taking energy from elsewhere.
What if that is like theft? Or leeching off of others?
I think the old making do with what you got may be wise.
Living w/o eating/drinking might be possible however it may also be more harmful than giving; that energy comes from somewhere. Its not just "prana" - it stems from somewhere.
Its the same with weed, I have a respect for people that grew their own weed while active; its a lot less of a loss in how it comes to be (at least here in DK where illegal and the cost of getting it is more so in blood than typical consumption due to the criminal backland required and funded by purchases). What if that Prana is like blood; produced by people eating, increasing their need to eat and thereby overall increasing consumption? If I were a vampire I'd live off of vegans to decrease my cost, however I'd rather prey on the predators demotivating people from going vegan!.