LONDON, April 13 (KUNA) -- A gene that contributes to obesity has been identified for the first time, promising to explain why some people easily put on weight while others with similar lifestyles stay slim, it was revealed here Friday.

People who inherit one version of the gene rather than another are 70 percent more likely to be obese, British scientists have discovered.

One-in-six people has the most vulnerable genetic make-up and weighs an average 3 kg more than those with the lowest risk. They also have 15 percent more body fat. The findings, published in the journal "Science," provide the first robust link between a common gene and obesity, and could eventually lead to new ways of tackling one of the most significant causes of ill health in the developed world, doctors said.

One-in-four British adults is classified as obese, and half of men and a third of women are overweight. Obesity is a main cause of heart disease, cancer and type 2 diabetes.

An adviser to the British Governments health spending watchdog said recently that the condition was a bigger national danger than smoking, alcohol or poverty.

If the biological function of the gene known as "FTO" can now be understood, it could become possible to design drugs that manipulate it to help people to control their weight.

"Even though we have yet to fully understand the role played by the FTO gene in obesity, our findings are a source of great excitement," Mark McCarthy, of the University of Oxford, southern England, who led the research, said.

"By identifying this genetic link it should be possible to improve our understanding of why some people are more obese, with all the associated implications such as increased risk of diabetes and heart disease." "New insights will hopefully pave the way for us to explore novel ways of treating this condition," he added.

When scientists understand more about the function of this first obesity susceptibility gene, they will be able to help people to lose weight more effectively despite their genes.