Here's why:  The kidneys can't function properly without enough water.  When they don't work to capacity, some of their load is dumped onto the liver. 

One of the liver's primary functions is to metabolize stored fat into usable energy for the body.  But, if the liver has to do some of the kidney's work, it can't operate at full throttle. As a result, it metabolizes less fat, more fat remains stored in the body and weight loss stops. 

Drinking enough water is the best treatment for fluid retention.  When the body gets less water, it perceives this as a threat to survival and begins to hold on to every drop. Water is stored in extracellular spaces (outside the cells).  This shows up as swollen feet, legs and hands. [Edema] 

Diuretics offer a temporary solution at best.  They force out stored water along with some essential nutrients. Again, the body perceives a threat and will replace the lost water at the first opportunity.  Thus, the condition quickly returns. 

The best way to overcome the problems of water retention is to give your body what it needs - plenty of water.  Only then will stored water be released. 

If you have a constant problem with water retention, excess salt may be to blame. Your body will tolerate sodium only in a certain concentration.  The more salt you eat, the more water your system retains to dilute it. 

But getting rid of unneeded salt is easy - just drink more water.  As it's forced through the kidneys, it takes away excess sodium. 

The overweight person needs more water than the thin one.  Larger people have larger metabolic loads.  Since we know that water is the key to fat metabolism, it follows that the overweight  person needs more water. 

Water helps to maintain proper muscle tone by giving muscles their natural ability to contract and by preventing dehydration.  It also helps to prevent the sagging skin that usually follows weight loss - shrinking cells are buoyed by water, which plumps the skin and leaves it clear, healthy and resilient. 

Water helps rid the body of waste.  During weight loss, the body has a lot more waste to get rid of - all that metabolized fat must be shed.  Again, adequate water helps flush out the waste. 

Water, can help relieve constipation.  When the body gets too little water, it siphons what it needs from internal sources.  The colon is one primary source.  Result?  Constipation.  But, when a person drinks enough water, normal bowel function usually returns. 

•     So far, we've discovered some remarkable truths about water and weight loss: 
• The body will not function properly without  enough water and can't metabolize stored fat efficiently. 
• Retained water shows up as excess weight. 
• To get rid of excess water you must drink more water.
• Drinking water is essential to weight loss. 

How much water is enough? 

On the average, an adult should drink eight 8-ounce glasses every day. That's about 2 quarts. However, the overweight person needs one additional glass for every 25 pounds of excess weight.  The amount you drink also should be increased if you exercise briskly or if the weather is hot and dry. 

Water should preferably be cold - it's absorbed into the system more quickly than warm water.  And some evidence suggests that drinking cold water can actually help burn calories. 

When the body gets the water it needs to function optimally, its fluids are perfectly balanced.  When this happens you have reached the "breakthrough point."  What does this mean? 

• Endocrine-gland function improves.
• Fluid retention is alleviated  - stored water is lost. 
• More fat is used as fuel because the liver is free to metabolize stored fat. 
  Natural thirst returns. 
• There is a loss of hunger almost overnight. 

If you stop drinking enough water, your body fluids will be thrown out of balance again, and you may experience fluid retention, unexplained weight gain and loss of thirst.  To remedy the situation you'll have to go back and force another "breakthrough." 

Weight Watchers-Lifeline Magazine, Winter 1998 

1. The body does not have a strong thirst mechanism to tell you when you are dehydrated-so a conscious program to drink at least 8 eight-ounce glasses of water daily is the best way of ensuring that we stay well hydrated.  Drink before you get thirsty.  If you wait until your body tells you that you're thirsty, it means you are already slightly dehydrated and not drinking enough water.
2. The body and mind can be affected by even a small water deficit.  It can cause fatigue, minor headaches and a general sense of not feeling mentally sharp. 
3. Water is the best means for hydration-water is inexpensive, readily available and has no calories.  For every cup of coffee or tea, or each glass of an alcoholic beverage, drink a glass of water. 
4. Caffeine and alcohol are diuretics and contribute to dehydration by causing us to excrete water, so you need to balance them by drinking more water.  Soft drinks containing caffeine will also contribute to dehydration. 
5. Increase water consumption when ill.  Drinking lots of water is one of the best protections against getting sick and one of the best means of healing when we're ill or just plain run down. 
6. You can tell if you are getting sufficient water by simply checking the volume and color of your urine.  It should be clear to pale yellow in color, and there should be lots of it.  The darker it is, and the less frequently you urinate, the more dehydrated your body likely is.