Why do models drink lots of water?
My understanding (being a biology grad student, and not a fashionista) is that models have two main reasons to drink tons of water: 1) it helps them to not eat food (try it yourself if you want to slim down -- next time you're hungry for a meal, drink 16-32 oz water first and see if it dampens your appetite); 2) it keeps the skin much clearer. Your skin is well tied in to your circulatory system, so all that fluid running around in your blood helps remove cellular detritus. Truly insane amounts of water -- gallons at a time -- can be fatal, so don't take this too far: huge amounts of water can cause your cells to swell, including your brain cells, which is what can get fatal. Some people are also concerned that large amounts of water would increase your exposure to pollutants. -- myself, I drink lots and lots when I can.