People who carry a specific variant of a gene have a preference to eat more fattening foods, and eat up to 100 more calories per meal, say scientists at the University of Dundee, Scotland.
A study investigated the eating habits of 100 children aged four to ten who took part in three eating tests, offering a range of healthy foods (grapes, cucumber, raisins) and unhealthy foods (crisps, chocolate, cheese). It was found that children with a particular variant of the fat-mass and obesity-associated gene (FTO) instinctively chose energy-dense foods with more sugar and fat.
The FTO gene has been shown in previous studies to be linked to an increased risk of becoming overweight or obese, but how it affects energy use and intake was not clear. In the current study, the presence of the gene was found to have no impact on the speed at which the body broke down food, or on how active people were. There was also no evidence of the people with the variant having trouble registering when they were full and should stop eating.
Professor Colin Palmer, of the Biomedical Research Institute, Ninewells Hospital and Medical School at the University, was involved in the past studies that identified the FTO gene, and was the lead researcher on this project. He says: 'this work demonstrates that this gene does not lead to obesity without overeating and suggests that obesity linked to this gene could be modulated by careful dietary control. What it effectively shows is that the people with the relevant variants on the gene have a trait which may lead them to eat more unhealthy fattening foods'.
It is thought that the variant of the FTO gene is carried by 63 per cent of people. Previous research has shown that people carrying one copy of the gene variant have a 30 per cent increased risk of obesity, while for those carrying two copies the increased risk is almost 70 per cent.
Professor Palmer stressed that the findings should not change the general advice to eat healthily and take regular exercise.
Dr Ian Campbell is the medical director of the UK charity Weight Concern, and he thinks that the findings should help us understand the difficulties of adopting a healthier lifestyle using will-power when their 'genetic make-up is telling them to do the opposite'. He says that 'we need to find ways to make a healthier lifestyle a more attractive and, therefore, an easier option'.
