6 Reason to Drink Water.

Here are six reasons to make sure you're drinking enough water or other fluids every day:

1. Drinking Water Helps Maintain the Balance of Body Fluids. Your body is composed of about 60% water. The functions of these bodily fluids include digestion, absorption, circulation, creation of saliva, transportation of nutrients, and maintenance of body temperature.

2. Water Can Help Control Calories. For years, dieters have been drinking lots of water as a weight loss strategy. While water doesn't have any magical effect on weight loss, substituting it for higher calorie beverages can certainly help.

3. Water Helps Energize Muscles. Cells that don't maintain their balance of fluids and electrolytes shrivel, which can result in muscle fatigue. "When muscle cells don't have adequate fluids, they don't work as well and performance can suffer," says Guest.

4. Water Helps Keep Skin Looking Good. Your skin contains plenty of water, and functions as a protective barrier to prevent excess fluid loss. But don't expect over-hydration to erase wrinkles or fine lines, says Atlanta dermatologist Kenneth Ellner, MD.

"Dehydration makes your skin look more dry and wrinkled, which can be improved with proper hydration," he says. "But once you are adequately hydrated, the kidneys take over and excrete excess fluids."

5. Water Helps Your Kidneys. Body fluids transport waste products in and out of cells. The main toxin in the body is blood urea nitrogen, a water-soluble waste that is able to pass through the kidneys to be excreted in the urine, explains Guest. "Your kidneys do an amazing job of cleansing and ridding your body of toxins as long as your intake of fluids is adequate," he says.

6. Water Helps Maintain Normal Bowel Function. Adequate hydration keeps things flowing along your gastrointestinal tract and prevents constipation. When you don't get enough fluid, the colon pulls water from stools to maintain hydration -- and the result is constipation