London: Being slim and trim doesn`t assure you a healthy life, say scientists who claim to have found a "lean gene" that helps people keep weight off but also raises their risks of developing diabetes and heart disease.
An international team from 72 institutions in 10 countries has found that the link is particularly strong in men, meaning those with washboard stomachs may not be quite as healthy as they think, the `Daily Mail` reported.
For their research, the scientists compared the genetic codes of more than 75,000 people with the ratio of fat to muscle in their bodies. This revealed an extremely common gene called IRS1 to be linked to leanness.
But while people are used to hearing about the many health benefits of being thin, IRS1 seemed to buck the trend.
Those with the gene had higher levels of dangerous blood fats and found it harder to process sugar, say the scientists.
This put them at a 20 per cent higher risk of developing heart disease and type 2 diabetes -- the form that develops in middleage and is often blamed on obesity.
As the gene is only linked to lower levels of fat stored just below the skin, known as subcutaneous fat, it may be that people who have IRS1 stash theirs elsewhere. If fat is wrapped around the heart, liver or other organs it could lead to life-threatening conditions, says the team.