Fat gene mystery
After identifying a gene that contributes to obesity two years ago, scientists have long suspected that genetic differences were responsible for weight gain and singled out the FTO gene as primarily responsible. People with a high-risk version of the gene weigh on average three kilograms more than those with a low-risk version.
Why should I be aware of this?
British scientists had estimated that one in six people who inherit one version of the gene rather than another are 70 per cent more likely to be obese. They have the most vulnerable genetic make-up and not only weigh an average 3kg more than those with the lowest risk, also have 15 per cent more body fat.
Even minor differences in a single gene may suppress the metabolism, which makes it difficult for the person to burn calories as effectively. In contrast, thinner people seem to use up energy more rapidly, expending it in excess heat.
Now, a team, led by Düsseldorf University in Germany, has found concrete evidence that the gene may control the rate of the metabolism, making its carriers more lean than those without it. With this discovery it could now become possible to design drugs that manipulate the gene to help people control their weight.
All about fat gene mystery
Following experiments on mice, the scientists came to the conclusion that those who had entirely FTO gene remained lean despite eating large amounts of food and being inactive.
These findings are significant as they will help promote research into the development of drugs that modulate FTO activity. It is still to be researched what the overall effect of inhibiting FTO in humans would be. But the scientists believe that, in man, FTO might have more complex effects on both food intake and energy expenditure than has been so far suggested.
Though it was known that genetic variation close to the FTO gene was associated with obesity in humans, the current research clearly established that this genetic variation was likely to influence obesity by altering the expression or function of the FTO gene.
What is FTO gene?
FTO comes in two varieties, and everyone inherits two copies of the gene. Those who inherit two copies of one variant were 70 per cent more likely to be obese than those who inherited two copies of the other variant. The 50 per cent of subjects who inherited one copy of each FTO variant had a 30 per cent higher risk of obesity.
Those in the highest risk group weighed an average of 3kg (7lb) more and those at medium risk were an average of 1.2kg heavier. In each case the extra weight was entirely accounted for by more body fat, not greater muscle or extra height. 
The researchers say it is important people understand there is a genetic predisposition to obesity as this may help people adopt a less prejudicial attitude towards the obese. 
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