Optimal function of the body is impossible without adequate hydration. There are 10 billion biochemical reactions that take place in the body every second of the day, and all of them are water dependent. Water’s primary role is to maintain a stable environment in and around the body’s cells, which allows both the assimilation of nutrients and the elimination of cellular waste. If you’re not drinking enough water, your body will not be able to flush out toxins. In general drinking half your body weight in ounces of water is a safe starting point, although this recommendation can vary depending on your own particular circumstances.