AUBURN - In a health-conscious nation, it seems as though everything that we have learned as children is under debate, including the amount of water that is needed to keep the body healthy. The once-popular notion that drinking six to eight glasses of water each day will ensure adequate hydration for the body may not stand true today.

Though this approach isn't supported by scientific evidence, many people use their body's thirst to determine how much water they should be drinking.

"Officials are now saying that they do not even know where the six to eight glasses of water each day rule originated," said Christine Gutelius, a registered dietitian and owner of the Nutritional Counseling Service in Auburn. "I guess that it has just been passed down through the generations and no one has ever questioned it."

So how much water should you drink each day to ensure proper hydration?

There are no easy answers to this question, as each individual has unique water needs that depend on many different factors, including the health of the person, activity levels and where they live.

"I have always found it difficult to drink six to eight glasses of water every day," said Justine Rice, of Auburn. "I try to every day, and then find myself feeling guilty that I just cannot seem to do it. These new findings are a relief."

Though no single formula can fit all people, understanding the ways that the body uses water and what factors may increase or decrease the body's water requirements will help guide each individual.

Water makes up, on average, 60 percent of the body's weight, with every system of the body depending on water for it to function properly. Lack of sufficient water in the body can lead to dehydration, a condition that occurs when there is not enough water in the body to carry on normal functions. Dehydration can drain the body of energy and leave the body feeling tired. Those at the highest risk of dehydration are the very old and the very young.

Signs of dehydration can include excessive thirst, fatigue, headache, dry mouth, little or no urination, muscle weakness, and lightheadedness.

For the body to function properly and to ensure proper hydration, the water that is lost every day through natural resources, such as sweating, exhaling and urination, must be replaced.

Typically, in a presumed healthy adult who engages in moderate activity, the body's internal thirst gauge will properly hydrate the body.

"I have not seen too much of a concern with my clients," Gutelius said. "I just tell my clients to drink water when they feel thirsty. Most healthy adults can rely on their internal thirst gauge. Of course, there are some instances, such as medications, high levels of activity and senior citizens who will need to drink more often, because they may not be able to rely on thirst. But for the average healthy adult, this should be sufficient."

According to The Institute of Medicine drinking enough water to quench your thirst every day should be enough.

You don't need to sip from your water bottle all day to satisfy your fluid needs.

Your diet, including the beverages you drink, can provide a large portion of what you need. In an average adult diet, food provides about 20 percent of the total water intake. The remaining 80 percent comes from beverages of all kinds.

"It seems that everywhere you look today, there is a bottle of water in someone's hand," Rice said. "It sometimes makes me feel inadequate that I do not do the same."

If someone is healthy and not in any dehydrating conditions, they should use thirst as an indicator of when to drink water.

But thirst isn't always an adequate gauge of your body's need for fluid replenishment. The older you are, the less you're able to sense that you're thirsty. During vigorous exercise, an important amount of your fluid reserves may be lost. So make sure that you're sufficiently hydrated before, during and after exercise.

Fruits and vegetables - besides being good sources of vitamins, minerals and fiber - contain lots of water.

For example, oranges are 87 percent water, and cucumbers are 95 percent water. Milk, juice and other beverages also have large amounts of water. Conversely, dried fruits, nuts, grain products and baked goods generally contain less water.

Alcohol, such as beer and wine, and caffenated beverages such as coffee, tea or soda, can contribute to your total fluid intake. But, the best beverage is still water. Water is calorie-free, inexpensive when drawn from a faucet or fountain, and readily available in and out of your home.

How to keep hydrated

Make a conscious effort to make water your beverage of choice. Nearly every healthy adult can consider the following:

- Drink a glass of water with each meal and between each meal.

- Take water breaks instead of coffee or tea breaks.

- Substitute sparkling water for alcoholic drinks at social gatherings.