I overheard a doctor saying 2 liters of water a day is an average amount of water that a human being need but the real deal is that, which came from the doctor as well, we need water as long as our body needs it. They just put on 10 glasses a day for an ideal intake of water that we need to fulfill so that our blood goes through the veins to transport food and vitamins to different parts of the body that needs it. You need to drink water as long as your body needs it means, you need to drink water, more than of 10 glasses for everyday of your life. Like me, I start drinking 4 glasses with an empty stomach from the start that I wake up in the morning. I drink a glasses before having my lunch and dinner. If I have a water intake, I feel energetic and I am less hungry. I always pee and that is the disadvantage but anyway, I am cleaning my body almost everyday so there are less toxins and danger for myself.