The body is made up of between 55 and 75 percent water. Muscle retains more water than fat, therefore, the leaner the body, the higher the percentage of water. Water is essential to regulate body temperature, provide lubrication for joints, help blood flow, regulate blood pressure, keep body systems functioning properly and keepskin elastic. Nearly every cell in our body requires water for proper function. Water is also necessary for digestion and the removal of toxins. Water keeps the liver and kidneys functioning well. Inadequate hydration can also cause sluggishness and headache due to a decreased flow of blood to the brain.

If you are trying to lose weight, water is useful to help you feel fuller, metabolize stored fat, and prevent water retention. Although preventing water retention by drinking more does not seem to make sense, it is actually true. When you do not drink enough water, your body goes into 'survival mode', retaining water to stay off dehydration. This causes water weight gain, as well as health problems.

Most people who do not drink enough water on a daily basis have a diminished ability to feel thirst. By the time thirst is felt, the body is already dehydrated. Once you begin drinking water daily, you will notice feeling thirst more often. The body requires at least six to eight, 8 ounce glasses of water a day. A good formula to know how much water is needed is to divide your weight in half, and figure that number in ounces of water. For example, for someone who weighs 140 pounds, 70 ounces of water would be required daily.