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.

When you’re low on fluids, the brain triggers the body’s thirst mechanism. And unless you are taking medications that make you thirsty, Guest says, you should listen to those cues and get yourself a drink of water, juice, milk, coffee — anything but alcohol.
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.

Food with high water content tends to look larger, its higher volume requires more chewing, and it is absorbed more slowly by the body, which helps you feel full. Water-rich foods include fruits, vegetables, broth-based soups, oatmeal, and beans.
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.

Drinking enough fluids is important when exercising. During exercise, they recommend that people start drinking fluids early, and drink them at regular intervals to replace fluids lost by sweating.
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.

You can also help “lock” moisture into your skin by using moisturizer, which creates a physical barrier to keep moisture in.
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.

When you’re getting enough fluids, urine flows freely, is light in color and free of odor. When your body is not getting enough fluids, urine concentration, color, and odor increases because the kidneys trap extra fluid for bodily functions.
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.
