Water in Diet
People can live for weeks without food. Without water, people will
die within days. The human body is 50% to 70% water.
Adults need at least two quarts, or eight cups, of water every day for good
health. Children need four to eight cups depending on age and size. The
easiest way to get water into the body is to drink it. Other fluids, and even
some foods, have water. These can help meet daily water needs. Milk, fruit
juice and even carbonated beverages are good sources of water. Drinks with
caffeine do not help meet daily water needs. Caffeine is a diuretic and causes
the body to lose water. Alcohol does not count toward meeting daily water
One of the most important jobs of water is to maintain
the body's fluid balance. This is a delicate balance of minerals. These
minerals, called electrolytes, dissolve in water. Electrolytes include sodium,
potassium and chloride. Electrolytes determine how much fluid stays in cells
and how much remains outside cells. An imbalance is not healthy. Too much water
inside cells is called "edema" or simply "fluid retention." Too much water
outside cells is called "dehydration."
Many medical conditions and drugs affect fluid balance.
The kidneys do most of the work of controlling fluid balance. People with
kidney disease often have special needs in terms of the amount they must drink.