Are you a victim of the hunger gene?

IF you always have room for dessert - and maybe even a second helping - you are about to be handed the perfect excuse. It's in your genes.

Are you a victim of the hunger gene?

IF you always have room for dessert - and maybe even a second helping - you are about to be handed the perfect excuse. It may be in your genes.

Scientists say that millions of people carry a rogue stretch of DNA that stops them feeling full and leaves them craving sugary and fatty foods.

The FTO gene, carried by more than half of the population, was discovered several years ago. But while researchers knew it made people fat, they didn't know how it did so.

Now they have learned that it keeps people feeling hungry, it could lead to new ways to tackle the obesity crisis. The 16 per cent of the population that carries two copies of the rogue DNA are 70 per cent more likely to become obese than those without the gene.

They eat up to 200 extra calories a day and are almost half a stone heavier than their average counterparts. And for those with the 'hunger gene' dieting is doomed to failure. Even those who have inherited just one flawed FTO gene - 49 per cent of the population - are 30 per cent more likely to be obese.

The British-led research team asked young men with and without the genetic flaw to rate their hunger before and after a meal. Volunteers' blood samples were then tested for ghrelin, a hormone that triggers feelings of hunger. Levels of ghrelin are usually high before we eat, and fall afterwards. But in the men with the 'hunger gene', levels remained relatively high after eating. They also felt hungrier than the others.

Next, the volunteers were shown pictures of various foods after they had eaten and asked how appealing they seemed. And despite just having had a meal, those with the gene still found cakes, pastries, chips and burgers highly tempting.

The scientists then used MRI scanners to peer into the volunteers' brains. Those with the 'hunger gene' lit up more at the thought of fatty and sugary foods, the Journal of Clinical Investigation reports.

Study leader Dr Rachel Batterham, of University College London, said that some of us were simply "biologically programmed to eat more.

"Not only do these people have higher ghrelin levels and therefore feel hungrier, their brains respond differently to ghrelin and to pictures of food. It's a double hit" she said.

The work, which was funded by the medical research charity the Rosetrees Trust and the Medical Research Council, could speed research into new obesity treatments.

"We know that ghrelin, and therefore hunger, can be reduced by exercise like running or cycling or by eating a high- protein diet" said Dr Batterham. There are also obesity drugs available.

Professor Steve Bloom, an obesity expert from Imperial College London, agreed the research would spur on the search for new treatments. It could also help in targeting any drugs to those who would benefit the most, he said.