If you're stuck on a weight loss plateau despite being faithful to your diet, the first thing you should check is your water intake. Research suggests that most Americans unknowingly suffer from mild, chronic dehydration, and that could be your problem!

So why should you care? Because water is important for your weight loss. In fact, water is needed for a wide range of the body's biochemical processes, but lets just look at what water does for dieters:

Water is essential for your body to metabolize stored fat into energy - so much so, that your body's metabolism can be slowed by relatively mild levels of dehydration. And the slower your metabolism, the slower your weight loss (and the greater your fatigue), until eventually your weight loss just crawls to a halt, and you hit the dreaded diet plateau.

Water is a natural appetite suppressant. In the hypothalamus, a region in your brain that controls appetites and cravings, the control centers for hunger and thirst are located next to each other, and there tends to be some overlap. This has both advantages and disadvantages for the dieter: on the down side, it means that chronic mild dehydration can confuse these control mechanisms, leading to feelings of hunger, rather than thirst. But on a positive note, it means you can use water to reduce your appetite. For example, in one University of Washington study, drinking a glass of water reduced nighttime hunger cravings for most of the dieters studied.

Water is an essential component of the processes that enable muscle to contract. This means that water helps to maintain muscle tone. Better muscle tone means a better looking body, and isn't that what dieting and weight loss is about?

Water also helps to prevent the sagging skin that often follows weight loss - water plumps the skin cells, giving the skin a younger and healthier look.

Water helps rid the body of waste. During weight loss, the body has a lot more waste to get rid of, as a byproduct of all that metabolized fat. So adequate water is essential to your health while dieting.

Water can even help with constipation. When the body gets too little water, it siphons what it needs from within, particularly from the colon. This leads to constipation. But normal bowel function usually returns with adequate water intake.

More generally, mild dehydration can cause a number of health problems, in addition to your diet plateau. The symptoms of mild dehydration can include: -

- Headaches & feeling light headed, as dehydration interferes with normal body processes, including waste disposal.
- Fatigue, as the body's metabolism is slowed - mild dehydration is probably the most common cause of daytime fatigue.
- Hunger & cravings due to weakening of the thirst mechanism
- Fluid retention as your body tries to hold on to the water it already has
- Constipation, as the body works to conserve its internal water sources

Not a pretty picture, is it? But once you get your water in balance, you reach the "breakthrough point", a concept pioneered by Dr. Peter Lindner, a California obesity expert. Once you've reached the breakthrough point, fluid retention eases, the liver and endocrine system start to function more effectively, you will start to regain your natural thirst and your hunger cravings will be significantly reduced. And so the end result of reaching and sustaining the breakthrough point in your water balance is that your body is able to metabolize fat more effectively.

So how much water should you drink daily, for a healthy and 'adequate' intake? First, a couple of basic principles:

1) The easiest way to tell if you are drinking enough water is to monitor the color of your urine: It should be clear or a very pale yellow in color. (but note that some supplements and medications may also affect your urine color).

2) Get in to the habit of drinking regular and adequate amounts of water. Never wait to drink until you're thirsty, because if you're feeling thirsty, then dehydration has already started to occur!

Having said that, an adequate water intake for a sedentary but normal-weight adult during cool weather, is generally recognized as 8 x 8 oz glasses.

Note that you need additional water in hot weather, when you lose more water through sweat.

You also need additional water when you exercise. Athletes attempt to enhance their performance by maintaining an optimal fluid balance while exercising, estimated to require 6 to 12 oz of fluid at 15 to 20 minute intervals. Even if you're not concerned about your athletic performance, you should consume a similar amount of water when exercising, in order to maintain adequate hydration.

And if you're overweight, you'll need an extra glass of water for each 25 pounds overweight, because the extra weight creates extra metabolic demand

But how do you manage to drink so much water? A typical recommendation from the weight loss experts is 3 glasses of water with every meal. That's 3 glasses with breakfast, 3 with lunch, and 3 with dinner. Plus, of course, additional regular water between meals when you're exercising or when its hot.

So if you're dieting, stalled on a weight loss plateau, or suffering some of the classic symptoms of dehydration, do, first of all, ensure that you have an adequate water intake. It could be the 'missing ingredient' in your diet regime.