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Water: An Essential for Good Health

August 2007

Karen Ensle Ed.D., RD, FADA, CFCS
Family & Community Health Sciences Educator
Rutgers Cooperative Extension of Union County

One small step that everyone can take to improve their physical health is to drink plenty of water. Water helps to keep the body hydrated and healthy. Individual needs vary, however, due to age, activity levels, where you live, and medications you may be taking. Below are some factors to consider.

Every system in your body depends on your internal fluid level. Lack of fluids can lead to dehydration, a condition that will cause many of your body systems to not work properly. It is a good idea to drink water each day, but remember that a significant (20%) amount of your fluids come from foods and 80% from water and beverages. Fruits and vegetables such as lettuce and melon provide a high percent of water by weight. Also, milk, juice, and other beverages contribute to fluids in your system. Drinking water, of course, is one of your best fluids because it is calorie-free, inexpensive, and readily available.

Every day, water is lost through your breath, urine, bowel movements, and perspiration. This fluid must be replenished by consuming beverages and foods that contain water. A healthy adult living in a temperate climate needs to replace about 2.5 liters a day, which includes water lost through breath, perspiration, and elimination of urine and waste. If you consume 8 cups of water and beverages daily along with your normal diet, your daily fluid will be replaced. The Institute of Medicine recommends that men consume roughly about 13 cups of total beverages a day and women consume about 9 cups per day. Beverages include water, coffee, tea, juices, sodas, and other fluids.

Thirst alone, is sometimes deceiving as a guide to how much one should drink. By the time one feels thirsty, he or she is often slightly dehydrated. As adults get older, they are less able to sense dehydration. Remember to make water your beverage of choice all day long. Try to drink a glass of water with each meal and between meals. Drink water before, during, and after exercise and substitute sparkling water with a twist of lemon or lime for alcoholic drinks at social events.

Dehydration occurs when you fail to take in an adequate amount of fluids. Mild hydration (1-2% of body weight) can make you feel sluggish and tired. Dehydration can be caused by heavy activity, lots of sweating, vomiting, or diarrhea. Here are some signs and symptoms of dehydration: mild to excess thirst, fatigue, headache, dry mouth, little or no urination, muscle weakness, dizziness, and lightheadedness. Mild dehydration will not cause complications if fluid is replaced quickly. For more severe cases, especially with young children or the elderly, dehydration can be life threatening.

Is it possible to drink too much water? In rare instances, a person’s kidneys may not be able to excrete excess water due to low sodium levels in the blood. This is known as “hyponatremia”. Marathon runners sometimes experience this imbalance. The average healthy adult does not. If you have concern about your fluid intake, check with your doctor or a registered dietitian who can help you determine the amount of water that is best for you.
For additional information about water in the diet, visit the Web site of the Mayo Foundation for Medical Education and Research,