Obese are born to put on weight, geneticists claim - Independent Online Edition > Health
Obesity is reaching epidemic proportions in the developed world because of the combination of high-calorie food and lack of exercise. In Britain, more than 20 per cent of the population is clinically obese, and half of men and a third of women are classified as overweight.
The study investigated variations in the DNA of a gene known as FTO - short for "fatso" - which occurs in patients with type-2 diabetes. More than 2,000 diabetes patients and 3,000 healthy "controls" took part in the study, published in the journal Science.
The scientists from the Universities of Exeter, Plymouth and Oxford searched the genomes of the diabetes patients and found a strong association between the disease and a certain variant of the FTO gene.
When the scientists expanded the study to look at 37,000 other people without diabetes, they found the same variant was also strongly associated with being overweight. The study found that carrying one copy of the FTO variant imparted a 30 per cent increased risk of obesity compared with a person with no copies.
Meanwhile, having two copies of the same variant increased the risk to 70 per cent - being on average 3kg heavier than a person with no copies of the FTO variant. About one in six white Europeans carry two copies of the FTO variant, according to Professor Mark McCarthy of Oxford University, who took part in the study.
"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," Professor McCarthy 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," he said.
Obesity is reaching epidemic proportions in the developed world because of the combination of high-calorie food and lack of exercise. In Britain, more than 20 per cent of the population is clinically obese, and half of men and a third of women are classified as overweight.
The study investigated variations in the DNA of a gene known as FTO - short for "fatso" - which occurs in patients with type-2 diabetes. More than 2,000 diabetes patients and 3,000 healthy "controls" took part in the study, published in the journal Science.
The scientists from the Universities of Exeter, Plymouth and Oxford searched the genomes of the diabetes patients and found a strong association between the disease and a certain variant of the FTO gene.
When the scientists expanded the study to look at 37,000 other people without diabetes, they found the same variant was also strongly associated with being overweight. The study found that carrying one copy of the FTO variant imparted a 30 per cent increased risk of obesity compared with a person with no copies.
Meanwhile, having two copies of the same variant increased the risk to 70 per cent - being on average 3kg heavier than a person with no copies of the FTO variant. About one in six white Europeans carry two copies of the FTO variant, according to Professor Mark McCarthy of Oxford University, who took part in the study.
"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," Professor McCarthy 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," he said.
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