I think I want to read this book.
Not only don’t you need to drink eight glasses of water every day, you cannot in any way make your complexion more youthful by drinking water. Your body’s water-balance mechanisms are tuned with the precision of a digital chemistry lab, and you cannot possibly “hydrate” your skin from the inside by drinking an extra bottle or two of Perrier. You just end up with pee sourced in France.
from The Big Thirst: The Secret Life and Turbulent Future of Water by Charles Fishman