PHILADELPHIA (CBS) – You hear it all the time. Drinking water is good for you and there’s no doubt it is.

Some of the most effective diets, diets that actually work, stress the role of drinking plenty of water and it is an excellent substitute, a refreshing one, for juice and soda.

Our bodies are almost two-thirds water, but there are startling facts out there. More than one out of two of us suffer chronic mild dehydration that can cause fatigue, headache, loss of appetite, dry eyes and mouth. The problem gets worse as we get older and you can’t always rely on being thirsty to drink fluids.

Here are the best suggestions.

Drink more during physical activity, but also drink on a routine basis. Instead of that snack, drink some water and don’t feel you have to purchase bottled water either. You can save a ton of money by drinking the free kind. We did it for many years.

Reported By Dr. Brian McDonough, KYW Newsradio Medical Editor