"The main thing I've heard is that the more water you drink during the day the better your skin will look because it will flush the toxins our of your system."

"I always take my water bottle with me when I exercise because I know it's important to get a lot of water."

It's one of those health tips we've all heard: Drinking lots of water—at least eight glasses a day is key to good health—helping us avoid dehydration and look and feel better. So do these claims hold water—or are they all wet?

Turns out the eight glasses a day rule has no basis in science. A panel of experts who reviewed the research concluded that most healthy people get enough water through normal consumption of foods and beverages.

What about the notion that extra H20 helps rid the body of toxins? That's the job of our kidneys, and there's no evidence that lots of water improves their effectiveness.

No dice either on the claim that chugging more water is good for your skin.

Though one study found that drinking two cups increased blood flow, it didn't reduce wrinkles or result in a smoother complexion.

Then there's the idea that water can promote weight loss. The evidence here is mixed, with some studies showing an effect and others finding none.

One thing, however, is clear: water may very well help you shed pounds if it replaces soda and other high-calorie beverages.

Certainly, there's nothing wrong with getting eight glasses a day, and it's a good idea to drink up if you live in a hot climate or engage in strenuous exercise.

But otherwise, simply eat a healthful diet and let thirst be your guide. Now that's advice we can all drink to.