How Much Water Does a Human Drink?

Water is essential for life.

Water is made up of hydrogen and oxygen, and it is the most common substance found on earth. Yet only one percent of the earth's water is suitable for drinking and all living things need water to survive.

Water in the Body

The human body is 66 percent water. Human blood consists of approximately 83 percent water, while lean muscle tissue and the brain are both 75 percent water. Babies are born with about 78 percent of their bodies made up of water. Because fat tissue contains less water than lean tissue, fatter people have a lower percentage of water than thin people.

Survival

While a person can survive without food for over a month, a person can survive for about a week without water, depending on prevailing conditions, like temperature and humidity.

Consumption

To maintain optimal health, humans must consume 2.5 quarts of water every day. This figure includes water that is drunk as well as water obtained from food eaten.

References

• U.S. Geological Survey: The Water In You
• United States Environmental Protection Agency: Water Trivia Facts