Obesity is one of the leading preventable causes of death worldwide. It has become one of the most serious public health problem of the 21st century with rates of adult and childhood obesity increasing.

Obesity is a condition in which excess body fat has accumulated to such an extent that health may be negatively affected. The primary treatment for obesity is dieting and physical exercise.

The anti-obesity pill, which works by preventing the stomach absorbing fat and this fat passes out of the body as waste, has shown that volunteers who took it with every meal shed an average of 10 lb after six months, the Evening Standard reported.

Dieters are advised to eat low fat foods, this is because Alli, a half-strength version of the prescription-only drug Xenical, works by stopping the body from absorbing about a quarter of the fat in food.

According the tabloid, tests showed that a short course of the pill also improves overall health by lowering blood pressure and cutting cholesterol levels.

Alli, which costs one pound, has been approved for sale in Britain without a prescription for the first time.

Those dangerously overweight will be able to buy the drug over the counter from chemists after a decision from the European medicines watchdog.