I believe the true healthy human would need zero food/water and the air supply all the water and minerals ever needed, but medical authors were writing 150 years ago that few people exist today in a healthy state and my best author, Hotema had a pet project of keeping track of news about Breathairians and there you find allot of info, etc.
Like the tree, nothing that breaths creates another cell out of anything but air, this was proven over 150 years ago! You can shut a potted tree up in a hot car on a sunny summer day and kill that tree within minutes, because it depends upon air to live as do humans.
We attempt to rob radation from foods and "IF" we were naked in the sun and in the open night air from birth up and followed God's design and not the monkey see, monkey do; then we could do with little to no food other than air/sunshine. But as it is, we follow the leaders known as the valley of darkness.