Body Water

Body Water is the water contained in the body's cells, and can generally be divided into intracellular (inside the cells) water and extracellular (outside the cells) water. As muscle contains a higher percentage of water than fat cells, body water often correlates with muscle mass - the more muscle mass you have, the more body water you will have as well

It is important to note that drinking water will not automatically and immediately turn into "body water". Body water changes slowly and is more reflective of overall hydration! If you drink a tall glass of water quickly, your device will likely interpret it as pure weight, as the body has not absorbed it yet.