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What Is Water?

Water is a combination of the elements hydrogen and oxygen. The way these elements are put together makes water a solvent, meaning it can dissolve most nutrients, making them available for the body to use. Water in the body comes mainly from two sources: liquids and foods. A small amount of water is produced when the body metabolizes the food you eat (converts it to energy). Water is removed from the body in urine and feces, perspiration and exhalation (breathing out air).

Most adult bodies are about 50-75% water. This is equivalent to about 12 gallons of water. Young people and men have a slightly higher percentage of water in their bodies because they usually have more muscle and less fat. (Muscle is made of more water than fat is.) Babies are composed of about 75% water.

Functions of Water

Water performs several functions in the human body. These include temperature regulation, waste removal, digestion, absorption, lubrication and transportation of nutrients.

Temperature Regulation – When the body becomes hotter than usual due to hard work, exercise, fever or exposure to heat, fluid is lost in the form of sweat (perspiration). This helps to cool the body, bringing the temperature closer to normal.

Waste Removal – Most waste products made by the body are water-soluble, so they can be excreted in the urine. The average person loses one to two liters of urine (mostly water) each day.

Digestion and Absorption – Nutrients from food are digested and absorbed into the bloodstream with the help of digestive juices. These juices are made mostly of water. Without the digestive juices, the body would not be able to get the nutrients from food.

Lubrication – Water lubricates the mouth in the form of saliva. This moistens the food so that it can be swallowed easily. Saliva also begins the digestion process.

Transportation – Blood, which is about 85% water, carries the nutrients from digestion through the body and delivers them to the right place.

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