Scientists have discovered how a key gene related to obesity works when it is faulty - which could signal the future prevention and even cure the health problem.

Since 2007 scientists have known that a gene named FTO was related to obesity and people with higher BMIs (Body Mass Index) have been found to carry a variant of this gene. But despite this, it had not been known how or why FTO was related to obesity.

Now, researchers at MIT and Harvard Medical School believe they have discovered that a faulty version of this gene causes energy from food to become stored as fat in the body rather than be burned, contributing to obesity.

The six types of obese individuals, according to research Show all 6 1 /6 The six types of obese individuals, according to research The six types of obese individuals, according to research Heavy drinking males The heavy drinking males had high levels of alcohol consumption – but above average levels of physical exercise. rex The six types of obese individuals, according to research Affluent healthy elderly A large number of the ‘affluent healthy elderly’ claimed some healthy practises, but still had high blood pressure and above average alcohol consumption. GETTY IMAGES The six types of obese individuals, according to research Physically sick but happy elderly The ‘physically sick but happy elderly’ group had a higher percentage of chronic health issues – such as diabetes and high blood pressure – but low levels of depression and anxiety. rex The six types of obese individuals, according to research Younger healthy females Young women did not have health problems associated with the obesity. rex The six types of obese individuals, according to research Unhappy anxious middle aged The ‘unhappy anxious middle aged’ group consisted of mostly women with high levels of insomnia, anxiety, depression and fatigue. Despite having the lowest alcohol intake of the groups, they also had the lowest sense of well-being and poor mental health. rex The six types of obese individuals, according to research Poorest health Those in the ‘poorest health’ group were likely to have the highest BMI, as well as not engaging in any healthy practises – such as exercise. Getty

In the study, published in the New England Journal of Medicine, scientists took cell samples from Europeans with either a healthy or faulty version of the FTO gene.

The findings showed that the faulty FTO gene ‘switched on’ two other genes – IRX3 and IRX5 – which have been identified as the “master controllers” of the process of thermogenesis as they can prevent the process in which energy is turned into heat, meaning it is instead stored as fat.

“Obesity has traditionally been seen as the result of an imbalance between the amount of food we eat and how much we exercise, but this view ignores the contribution of genetics to each individual’s metabolism,” senior author Manolis Kellis said.

Being overweight and obesity has been closely linked to 10 common cancers (Getty Images)

Obesity has been identified as one of the biggest public health challenges of the 21st Century and already affects 500 million people worldwide. It has been credited with contributing to potentially fatal disorders such as cardiovascular disease, type 2 diabetes and cancer.

But the discovery means there could be a cure on the way. “It’s a big deal,” Dr Clifford Rosen, a scientist at Maine Medical Centre Research Institute, and an associate editor of the medical journal told the Associated Press.

“A lot of people think the obesity epidemic is about eating too much,” but fat cells play a role in how food is used, he said.