We've all been there: you start a new diet, lose weight for a few weeks; then the weight creeps back on. In desperation you try a different diet and go through the same cycle. It's called the yo-yo effect.

One of the best kept secrets of a successful diet is to drink lots of water - it's a secret because water is free, nobody is going to make a lot of money selling you that idea! Studies show that as many as 75% of the population is seriously dehydrated. When the body is thirsty it sends a message to the brain requesting a drink. Unfortunately, the message is very similar to the signal that asks for food, so most people snack when what their bodies really need is a drink.

A person of average build requires 8 glasses of water each day - each glass should hold 8 oz. If you are overweight you need more: an additional glass for every 25 pounds of excess weight.

It has to be water. Cups of tea or (caffeinated) coffee don't count as both are diuretics and actually rob the body of water. Indeed, for every cup of coffee or tea, or glass of cola you drink you need another cup of water in addition to the 8 glasses!

So what is so great about drinking water?

- If you are not drinking enough water your body will store as much as possible as a defense mechanism. Retained water adds to your weight. If you have a water retention problem, drink more water! It may sound crazy but once the body is trained to expect a regular supply it will store less, leading to a reduction in your weight.

- A study by the University of Washington found that one glass of water before bed prevented night-time hunger pangs in nearly 100% of the participants in the study..

- Water is a natural appetite suppressant and it helps the body to use up stored fat. Insufficient water may cause an increase in fat deposits as the kidneys will not function properly, passing some of their duties to the liver which is then unable to metabolize stored fat into energy..

- Constipation is a symptom of dehydration. Increasing your water intake should cure the problem..

- Migraine-type headaches are often caused by insufficient water..

- Your kidneys remove waste matter such as uric acid, lactic acid, and urea; all of which need to be dissolved in water. Insufficient water intake can lead to kidney damage.

Next time you start a weight management program, make sure you drink enough water; it will increase your chances of success.