Water in diet

Function

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. It makes up saliva and the fluids surrounding the joints. Water regulates the body temperature through perspiration. It also helps prevent and relieve constipation by moving food through the intestines.

Food Sources

You get some of the water in your body through the foods you eat. Some of the water is made during the process of metabolism. But drinking water is your main, and best source, of water.

You also get 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 effect -- they cause the body to release water.

Side Effects

If you do not drink enough water each day, the body fluids will be out of balance, causing dehydration. When dehydration is severe, it can be life-threatening.

Recommendations

Although there is no research to identify the exact amount of water you should drink, experts usually recommend drinking six to eight 8-ounce glasses of water daily.

Alternative Names

Diet - water; H2O

References

Bistrian B. Nutritional assessment. In: Goldman L, Ausiello D, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 221.

Wolf R, Wolf D, Rudikoff D, Parish LC. Nutrition and water: drinking eight glasses of water a day ensures proper skin hydration - myth or reality? Clin Dermatol. 2010;28:380-383.

Update Date: 8/15/2011

Updated by: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.