Water accounts for 60 percent of your body’s weight, but this water supply is routinely depleted through perspiration, urination, certain health conditions, or the consumption of caffeinated products. Since maintaining a sufficient water level is crucial to maintaining a healthy body, many experts recommend drinking eight 8-ounce glasses of water a day. However, as with most medical advice, there are other experts who refute this advice, and point to other dynamics that should be considered when determining an individual’s daily water consumption needs.

Water: What’s the Big Deal?

Water aids in digestion, transports nutrients throughout your body, and assists the immune system. In addition, water helps to regulate your body temperature, provides lubrication and cushioning for your joints, and provides protection for your spinal cord. If that’s not enough, water also removes waste from your body through perspiration, urination, and bowel movements.

Water and Weight Loss

An article on the CNN Health website revealed that drinking water also helps you lose weight. According to a study performed by Dr. Brenda Davy of Virginia Tech, test subjects who consumed two glasses of water half an hour before each meal lost substantially more weight than the study participants who did not drink water before meals.

In another study conducted by Dr. Davy, test subjects consumed 75 fewer calories during meals when they drank water beforehand. As a point of reference, if you ate 75 fewer calories during two of your three daily meals, you could lose 14 pounds in the course of a year. One theory is that water fills you up, so drinking water before meals may prevent overeating.

The results of another study, which was presented at a meeting of the Obesity Society, examined 240 overweight women between the ages of 25 and 50 who were put on one of several popular diets plans. Before the start of the diet, each woman normally consumed 2 cans of some sort of sugary drink – juice or soda – every day. The dieters who replaced their sugary drinks with water lost an average of 5 pounds more per year than the dieters who continued to drink sugary beverages. Also, the women who drank more than 4 cups of water lost at least 2 more pounds a year than the dieters who did not drink as much water.

How much water is enough?

Mayo Clinic recommends drinking eight 8-ounce glasses of fluids each day, pointing to the fact that juice and milk are primarily water-based beverages. The Clinic also notes that even coffee, tea, beer, and other caffeinated drinks have a high water content – although they warn against relying on these types of beverages to meet the majority of your water needs. Mayo Clinic recommends water as your primary water source because it is inexpensive – unless you buy the pricey brands of bottled water – and it contains no calories.

However, the Clinic also states that there is no conclusive evidence to support the 8-glass theory. It hypothesizes that the 8 x 8 phrase is easy to memorize.

The Centers for Disease Control and Prevention (CDC) agrees that most Americans get the water they need through beverages. However, they also include certain foods as a source of water. For example, broth soups, melons, and oranges have an 85% to 95% water content. To combat calories from sweetened drinks, the CDC recommends the consumption of sugar-free beverages.

Baylor College also recommends the consumption of at least eight 8-ounce glasses of water daily. However, kidney specialist Heinz Valtin, who is also a professor at Dartmouth University, refutes the necessity of consuming 8 glasses of water – or even fluids – a day. Valtin states that he found no scientific evidence to support 8 x 8, and says excessive water consumption leads to a higher risk of exposure to contaminants, and the inconvenience and embarrassment of having to frequently urinate. In addition, he notes that those who try to meet 8 x 8 using bottled water incur an unnecessary expense.

How to Tell If You’re Not Drinking Enough Water

Consuming an insufficient amount of water can cause your body to become dehydrated. In this state, your body does not have enough water to perform normal body functions. According to Mayo Clinic, if you don’t drink enough fluids, you may notice that you’re thirsty most of the time, and you’re producing less than 6 cups of urine a day. Your urine will also be dark in color – although taking certain vitamins and prescription drugs can also darken your urine.

For those of you who don’t measure the amount of urine you pass on a daily basis, Baylor University notes that a properly hydrated person will urinate every hour or so, and will also have regular bowel movements.

You may need to increase your water intake if you live in a humid climate, are an athlete, or you are physically active. Infants and children have a higher water turnover level, and older adults have a less acute sense of thirst and a decreased ability to conserve water, so they should be monitored for dehydration if there is a concern that they are not drinking enough fluids. In addition, individuals with a health ailment such as diarrhea, vomiting, or fever, also need to consume more water to replace lost or depleted fluids.

Caffeine lovers who overindulge their habit may also find that this diuretic causes an increase in urine production, and need to drink more fluids to replenish their body’s water supply.

In addition to increased thirst levels, constipation, and decreased or dark-colored urine, other symptoms of mild to moderate dehydration include:

• Sleepiness
• Tiredness
• Dry mouth
• Inability to produce tears
• Headache
• Dry skin
• Dizziness

Extreme dehydration causes more severe symptoms, which include:

• Extreme thirst
• Little or no urination
• Low blood pressure
• Rapid heartbeat and rapid breathing
• Fever
• Delirium or unconsciousness

Can you drink TOO much water?

Although rare, it is possible to drink too much water. Hyponatremia is a condition that occurs when you increase your water intake but your sodium levels remain the same, or your body loses a lot of sodium without losing a proportional amount of water. The excess water causes the body’s cells to swell; however, the brain’s skull does not provide adequate space for expansion. Brain swelling is the most obvious sign of hyponatremia, and other symptoms include loss of appetite, fatigue and confusion. In addition, drinking large amounts of water will cause convulsions and hallucinations in someone suffering from this condition.