Coconut water is the clear liquid found inside a young coconut. It has been used for centuries as a refreshing drink and can be served either chilled or at room temperature. Coconut water is naturally fat-free, cholesterol-free, and very low in calories. Coconut water is a natural isotonic beverage, which means that it has the same level of sugar and salts as your body's fluids. This makes it easy for your body to absorb and digest. In fact, many people drink coconut water when they have an upset stomach because it helps to restore their electrolytes without further upsetting their system.