Is Water An Important Part Of A Healthy Diet?

The human body consists of nearly 70 percent water. For the body to function properly, the average person needs to consume about 2 L of liquid per day. Your intake varies depending upon the food you eat, environmental temperature and humidity and your activity level, among other factors. By choosing foods rich in water, you can ensure that you meet the daily recommended intake for this precious resource.

Functions

Although calorie-free, water is considered a nutrient because it serves several physiological functions that are essential to life. For example, water transports nutrients to cells and assists in the removal and excretion of waste products. In addition, it regulates body temperature, moisturizes the skin and catalyzes chemical reactions. You can last several weeks without food, but only a few days without water.

Recommended Intake

To replace the amount lost through urination, perspiration, breathing and bowel movements, the USDA recommends that women consume 2.7 L of water per day. Men should consume 3.7 L per day. This is the equivalent of roughly 12 to 16 cups per day, respectively. Sources include all beverages, as well as the moisture present in foods. Fruits and vegetables are moisture-rich, while processed foods lack moisture.

Considerations

Since the standard American diet is rich in processed foods, which lack moisture, the USDA estimates that only 20 percent of water consumption comes from the food you eat, and therefore 80 percent should come from beverages, which include tea, coffee and sodas. According to Don Colbert, M.D., when consumed with meals, water dilutes stomach juices and washes out enzymes, delaying digestion. Therefore, drinking 2 or more liters of water in addition to a day's worth of calories may be inferior to consuming the equivalent amount of water packed naturally in food.

Food Sources

Fruits and vegetables derive as much as 90 percent or more of their weight from water. Watermelons, tomatoes, lettuce, eggplant and celery, for instance, contain more than 90 percent water. Apples, peaches and oranges are roughly 85 percent water. At 95 percent, a cucumber is almost pure water. Assuming an average water content for fruits and vegetables of 75 percent, each piece of fruit or cup of vegetables is the equivalent of 6 oz. of water. Ten servings of these foods amounts to nearly 2 L of water, mixed with vitamins, minerals and fiber.

Water and Exercise

If you are active, be sure to drink enough water to replace fluids lost during exercise. It is not uncommon to lose as much as 2 or 3 lbs. of fluid, in your breath and sweat, in an hour-long workout. An easy way to determine your fluid needs is to weigh yourself before and after working out. Two pounds of fluid equals 1 L, or about 4 cups of water.

Risks

No upper limit for water has been set, because normal kidneys can handle 24 oz of fluid per hour, which is more than most people are likely to drink. Symptoms of water intoxication include hyponatremia, or low blood sodium, which can result in heart failure, and rhabdomyolysis, or damage to skeletal muscle, which in turn can lead to kidney failure. This is sometimes seen in endurance athletes who replace water lost through sweat without consuming an appropriate amount of sodium.

Warning

Symptoms of dehydration include thirst, decreased urine output, headache, dizziness and muscle weakness. To ensure you are meeting the recommended intake for water, take note of the frequency and quality of your urine. You should urinate every two or three hours, and the color should be light yellow, similar to the hue of lemonade. Any darker or less frequent, and you may need to increase your water intake.