How ’obesity gene’ triggers weight gain

An international team of researchers has discovered why people with a variation of the FTO gene that affects one in six of the population are 70 per cent more likely to become obese. A new study led by scientists at UCL, the Medical Research Council (MRC) and King's College London Institute of Psychiatry shows that people with the obesity-risk FTO variant have higher circulating levels of the 'hunger hormone', ghrelin, in their blood. This means they start to feel hungry again soon after eating a meal. Real-time brain imaging reveals that the FTO gene variation also changes the way the brain responds to ghrelin, and to images of food, in the regions linked with the control of eating and reward. Together these findings explain for the first time why people with the obesity-risk variant of the FTO gene eat more and prefer higher calorie foods compared with those with the low-risk version, even before they become overweight. The research, funded by the MRC and the Rosetrees Trust, is published today in the Journal of Clinical Investigation . Individuals with two copies of the obesity-risk FTO variant are biologically programmed to eat more.