Approximately 60 percent of the human body is made of water. Water plays a role in all of the systems in your body. It provides the means for your kidneys to work by filtering out toxins. Water is essential to life making up most of your blood that circulates and provides nutrients and oxygen to your body. Water is distributed throughout your body, but muscles contain more water than fat tissue.
Your muscles contain 75 percent water, same as the amount in your brain. Fat contains only 10 percent water. This is less than bone, which contains 22 percent water. The difference in fat and muscle tissue may be due to glycogen. Muscle contains glycogen, the storage form of glucose; glycogen is 75 percent water.
Men tend to carry more water than women. This has to do with the amount of body fat in a woman versus a man. Women carry more essential fat than men. This is the fat around the body that is necessary, including reproductive fat in the breasts and around the uterus. Men inherently have a larger amount of skeletal muscle. For these reasons, men contain about 60 percent water while women have 55 percent water.
At birth, a baby is 78 percent water, but this drops to 65 percent by the first birthday. In the elderly, body water content begins to fall. As you age, you experience something known as sarcopenia. This is a progressive decline in the amount of muscle mass you have. Since muscle mass dwindles with age, so does the water content of the body.
Water consumption is important for replacing fluids that you have lost throughout the day. According to the Institute of Medicine, water consumption recommendations vary by gender. Men should consume 3 liters of water each day. While women need to take in 2.2 liters per day.
- U.S. Geological Survey: The Water In You
- MayoClinic.com: How Much Should You Drink Everyday?
- National Health Association: Does Muscle Weigh More Than Fat?
- Exercise Physiology: Human Bioenergetics and Its Applications; George A. Brooks, et al.
- Colorado State University: Nutrition and Aging