Scientists believe they've discovered what causes the middle-aged spread, and, more to the point, how to stop it.

Researchers found that signals within the 2 day diet strong brain which tell us to prevent eating when full become less efficient with age.

Even though it may only mean we eat a number of forkfuls of food, the additional calories mean about 1lb of extra weight each year.

However, the signals can be reactivated through drugs which have already been developed to help obese people slim down.

This means that medication could be given to people in their twenties or thirties to regulate appetite. "It could be utilized as a preventative and stop the middle-aged spread altogether," said Professor Lora Heisler, chair in human nutrition in the University of Aberdeen, in which the study was conducted.

A little set of cells within the brain are responsible for producing hormones called pro-opiomelanocortin (POMC) peptides which regulate appetite and the body weight.

However, as people approach middle age those cells stop sending as numerous signals, which is harder to feel full.

The extra drink and food consumed could result in a normal person carrying an additional 20 to 30lb by middle age.

A brand new drug, lorcaserin, that is obtainable in the united states, can switch the signal back on fully, but it is not licensed in Europe.

"Many people wonder why the middle-aged spread happens. You believe to yourself, 'I haven't changed anything but I'm putting on the weight," said Prof Heisler.

"More than 1 / 2 of individuals the united kingdom are overweight and one in four is clinically obese. And the simple fact could it be is extremely difficult to slim down once it is there, so if we're able to help people prior to them getting to that particular stage then that is obviously beneficial."

In the UK several third of men and women will be clinically obese by 2030, costing the NHS an extra ?¡§o19.2bn (€24bn) a year.

Tam Fry of the National Obesity Foundation said the drugs could help fat people but advised against giving them to young adults before they gained weight.

"We're heading within the right direction lida old and drugs such as this may be the Ultimate goal in fighting the obesity epidemic," he explained.

"But the issue using the middle-aged spread is it is caused by a number of factors. if you exercise and eat healthily a large amount of these problems will go away."