They are hereditary with 70 % more exposed to obesity

Apr 19, 2007 13:39 GMT  ·  By

With one more bite you have increased your waist size, while the skinny prick beside you engulfs hamburger after hamburger, ice-cream after ice-cream, and nothing...

For long, a genetic component of the issue has been suspected, but now scientists come with the clearest evidence yet between genes and obesity, explaining why at the same amount of food, some people get overweight while others stay slim or even get thinner.

The new research made by a mixed team from the universities of Exeter, Plymouth and Oxford describes a genetic pattern that confers an individual a 70 % higher risk of being obese compared to other genotype (genes' pattern) variants.

The researchers could not find the exact mechanism by which these genes turn an individual exposed to obesity but this is a start for a detailed understanding of the reason why some individuals present the genetic predisposition to being fat.

"As a nation, we are eating more and doing less exercise, and so the average weight is increasing, but within the population some people seem to put on more weight than others," said Professor Andrew Hattersley from the Peninsula Medical School in Exeter.

"Our findings suggest a possible answer to someone who might ask: 'I eat the same and do as much exercise as my friend next door, so why am I fatter?" "There was clearly a genetic component to obesity," added Hattersley.

The investigation focused on DNA variations (called alleles in genetics) of the gene named FTO (from "fatso") encountered in patients with type-2 diabetes.

The research was made over a pool of about 2000 diabetes patients and 3000 healthy "controls".

The team spotted a significant link between the disease and a certain FTO allele.

Then they expanded the investigation on 37,000 other subjects without diabetes and discovered that FTO allele was also clearly linked to being overweighed.

People carrying one normal FTO and one FTO allele displayed a 30 % higher risk of obesity than people carrying just two normal FTO genes.

Those carrying just two copies of the allele presented a 70 % higher risk for obesity.

And almost 17 % of the white people carry two alleles.

Imagine that the allele in combination with the normal FTO is even more common!