People who carry a variant of the so-called obesity gene FTO eat roughly 100 more calories per meal, new research suggests.

Professor Colin Palmer of the University of Dundee in Scotland and colleagues studied the eating habits of 100 children aged between 4 and 10. Each child took part in three eating tests, where they were offered a range of different foods, including: ham, cheese, crackers, crisps, raisins, grapes, cucumber, carrot, chocolate buttons, water, orange juice, and bread rolls.

Results showed that the children with the FTO gene variant were significantly more likely to choose foods containing high levels of sugar and fat, thus suggesting that they were instinctively drawn to those types of food. Furthermore, because of the types of food chosen by the children with the FTO gene variant, they ate approximately 100 calories more during each of the three eating tessts.

Results also showed that the gene had no impact on metabolic rate or measures of physical activity. In addition, the researchers were unable to find any evidence to suggest that children carrying the FTO gene variant did not know when to stop eating, thus suggesting that the variant does not affect satiety factors.

“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,' said Professor Palmer in a news release. “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. I would stress that this is a trait, and not an absolute occurrence. While strong genetic effects have been found in extremely rare cases, most obesity is associated with rather weak genetic tendencies that are modifiable by diet and exercise.”

News release: Obesity gene link to a preference for fattening foods. University of Dundee. December 11th 2008.