Anyone who has ever tried to lose weight has undoubtedly heard the advice, “Drink lots of water.” But can water really help you lose weight? If so, how much water do you have to drink? Are there any special rules for using water for weight loss?
Water and Your Body
Your body is about 70 percent water. Your body needs water to circulate blood and nutrients through your body as well as to flush toxins and waste away. Water also helps to regulate your body temperature through sweat.
When your body does not get enough water, your heart and other muscles cannot function at their peak. Your body cannot maintain the right temperature and you will begin to feel weak. You may become nauseous and vomit. You may even lose consciousness.
It is possible to drink too much water. When that happens, you may experience headaches, nausea and seizures. This condition is called hyponatremia (low blood sodium) and is potentially fatal. However, while endurance athletes (such as ultra-marathoners and “Ironman” participants) are warned against the dangers of drinking too much water, it’s actually more a risk among slower amateur-enthusiast runners, according to Angus H.N. Whitfield of the British Journal of General Practice. Whitfield says this is because novice runners are cautioned against dehydration but not against water intoxication.
According to the American Council on Exercise (ACE), it is best to drink 16 to 24 oz. of water two hours before exercise and another 8 oz. 15 minutes before exercise. Drink 16 oz. of water every 20 minutes of exercise and 8 oz. of water within 30 minutes of finishing exercise. ACE also recommends drinking 16 to 24 oz. of water for every pound of body weight lost during exercise.
A good rule of thumb to determine whether you are drinking enough water is to look at your urine. If it is clear or pale yellow, then you are drinking enough water. If it is dark yellow or golden, you need more water.
Will extra water help?
Dr. Gabe Mirkin of Stanford University’s wellsphere.com website says that water can help you feel full at the end of a meal. However, that sensation lasts only a minute or two, leaving you feeling hungry. Therefore he does not recommend drinking extra water to lose weight.
Mirkin instead recommends eating foods high in fiber and water, such as fruit, vegetables, whole grain and beans. A day’s food, he says, contains about four cups of water. In addition, when your body burns calories, the chemical reactions generate another two cups of water.
It has long been believed that drinking cold water has a "thermogenic" effect. That is, the body needs to burn more calories (energy) to warm itself from the cold water, thus promoting weight loss. However, a study at the University of Freiborg, Switzerland, found otherwise. "Drinking distilled water at room-temperature did not increase energy expenditure and cooling the water before drinking only stimulated a small thermogenic response, well below the theoretical energy cost of warming the water to body temperature," according to a report on the Journal of Clinical Endocrinal Metabolism.
The authors of the report did encourage people trying to lose weight to drink water when thirsty in order to avoid dehydration.
While Mirkin says that drinking extra water will not help you eat less during a meal, there is still a way to use water to lose weight. When tempted by a high-calorie treat, drink a glass of water. The time it takes to drink it can distract you. The brief feeling of stomach fullness may last long enough for you to forgo the treat.