Yes, if given by a surgically implanted feeding tube.
"Is withholding food and water until someone dies the same as "letting them die" -- or is it more like killing them?"
If the food and water is being delivered by a surgically implanted feeding tube, then withholding food and water until someone dies is the same as "letting them die".
"Who would you deny food and water to?"
Me? No one.
But I would withhold food and water if it was being delivered by a surgically implanted feeding tube, if I was their caregiver, and if they had requested I do so under certain conditions to allow them to die.
Why do you ask? Why is this about me and what I would do? Just being nosy?
"Dead people should be taken off (subject to their clearly stated will for such eventualities)."
But if they're PVS or severly brain damaged they shouldn't, even if their will clearly states they want this?