By Diet and Fitness Expert
Dr. Melina Jampolis
Physician Nutrition Specialist
Source: http://edition.cnn.com/2009/HEALTH/expert.q.a/04/10/water.losing.weight.jampolis/index.html
Research does suggest that drinking plenty of water may help you
lose weight. An abstract by Dr. Brenda Davy, associate professor of
human nutrition, foods and exercise at Virginia Tech, presented at last
year's obesity conference in Phoenix, Arizona, showed that people who
drank two glasses of water 20 to 30 minutes before every meal lost
weight more quickly initially and lost significantly more weight than
those who didn't.
In another study by Davy and her group,
published last year in the Journal of the American Dietetic
Association, she found that people who drank water before meals ate an
average of 75 fewer calories at that meal. This may not seem like much,
but if you ate 75 fewer calories at lunch and dinner for the next year,
you could lose about 14½ pounds! In addition, being even 1 percent
dehydrated can cause a significant drop in metabolism, which can also
interfere with weight loss.
Finally, it is very difficult for
the body to differentiate hunger from thirst. If you don't drink enough
water throughout the day, you may mistake thirst for hunger and eat
more than you really need, which can also impair weight loss. So
staying well hydrated is important, particularly if you are trying to
lose weight. And don't forget to eat lots of water-based foods like
soups, vegetables and low-fat dairy, which are equally important for
weight loss, as they lower the calorie density of meals. That can help
you reduce calories without reducing portions.
To answer the
second part of your question, yes, drinking massive amounts of water
(gallons and gallons) can cause a dangerous condition known as
hyponatremia (low sodium levels in the blood), which can cause
confusion, irritability and seizures and may even lead to a coma.
This
condition is very rare in healthy people but can sometimes be seen in
the elderly or in endurance athletes who sweat significantly and drink
water only to replace lost fluids. Most people should be far more
concerned with not drinking enough water versus drinking too much.