MedlinePlus Medical Encyclopedia: Water in diet

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Water in diet

Contents of this page:
Alternative names Definition Function	Food Sources Side Effects Recommendations

Alternative names

Diet - water; H2O

Definition Return to top

Water is a combination of hydrogen and oxygen; it is the basis for the fluids of the body.

Function Return to top

Water makes up more than two-thirds of the weight of the human body. Without water, humans would die in a few days. All the cells and organs need water to function.

Water serves as a lubricant and is the basis of saliva and the fluids surrounding the joints. Water regulates the body temperature through perspiration. It also helps prevent and alleviate constipation by moving food through the intestinal tract.

Food Sources Return to top

Some of the water in our body is obtained through foods we eat (those that are 85-95% water), and some is the by-product of metabolism. But drinking water is our main, and best, source of water. We also obtain water through liquid foods and beverages, such as soup, milk, and juices. Alcoholic beverages and beverages containing caffeine (such as coffee, tea, and colas) are not the best choices because they have a diuretic (water-excreting) effect.

Side Effects Return to top

If adequate water is not consumed on a daily basis the body fluids will be out of balance, causing life-threatening dehydration.

Recommendations Return to top

Six to eight 8-ounce glasses of water, or half of the body weight in ounces, are recommended on a daily basis. For example, if you weight 140 pounds, you will need to drink 70 ounces of water.

Milk, juice, and soup should not be substituted for the entire water requirement. Caffeinated and alcoholic beverages (due to their diuretic effect) would not be appropriate substitutes at all. Carrying a water bottle and drinking at regular intervals will help you obtain the recommended amount of water.

Update Date: 10/17/2003

Updated by: David Webner, M.D., Sports Medicine Fellow, Crozer-Keystone Family Practice Program, Springfield, PA. Review provided by VeriMed Healthcare Network.

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