They may be the envy of their fuller-figured friends, but slim people shouldn’t feel too self satisfied. Being trim does not guarantee they are healthy. For the same reason, if you buy wow gold, is that mean this is the only one who can provide cheap wow money?

Researchers have found a so-called ‘lean gene’ that helps them keep weight off but also raises their odds of developing diabetes and heart disease. The link is particularly strong in men, meaning those with washboard stomachs may not be quite as healthy as they think. 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 we 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. This put them at a 20 per cent higher risk of developing heart disease and type 2 diabetes – the form that develops in middle-age 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.

Professor Jeremy Pearson, of the British Heart Foundation, said: “these results reinforce the idea that it is not just how fat you are, but where you lay down fat that’s particularly important for heart risk.” Fat stored internally is worse for you than fat stored under the skin.