The man was badly disfigured after being attacked by a bear in 2004; two thirds of his face was replaced in an operation that lasted 14 hours.

The man had lived a reclusive existence because of his horrific disfigurement.

Han Yan, deputy director of the plastic surgery department of the Xijing military hospital in Xian, capital of Shaanxi province, says the surgery was even more complex than the face transplant in France in November last year.

It comes less than five months after doctors in Amiens carried out the world's first face transplant on Isabelle Dinoire, 38, whose lips and nose were torn off by her own dog.

Reports say the Chinese patient was given a new cheek, upper lip, nose, and an eyebrow from a single donor.

Although he is said to be making a good recovery it is expected to take six months before feeling is restored to the new face and the man will need help to overcome psychological and ethical problems.

According to the reports Xijing hospital successfully performed a facial skin transplant operation on a rabbit in December last year, transplanting half the skin tissue from a New Zealand rabbit.

Apparently a fortnight later, the rabbit was in good condition with the eye on the transplanted side blinking naturally.

The claims, yet to be verified by independent experts, signal the nation's growing scientific prowess while some questions remain about its regulation of medical experiments.

In the last decade, the Chinese government has provided considerable financial support for scientific research, from aerospace to biotechnology, in order to create, by pooling expertise and resources, research centres to rival those of the western world.

China, which was the third country to have a successful manned space programme, and has won accolade from international scientists for its its gene research.

Many scientists believe that many obese people are so because of their genes but this is the first study to identify a genetic factor in obesity and will be a relief to the many obese people around the world who have been puzzled and distressed at their never-ending war against fat and wondering why they find it so hard.

What is clear is, whatever the theory absolutely no difference has been made to the speed at which obesity is spreading around the world.

Christman says they believe the other nine or so genes will be found very soon and there will be many such discoveries over the next few years which will ultimately allow researchers to find the molecular pathways of obesity, which can then be targeted by drugs.

The research is published in the current edition of the journal Science.