Fat teens? Blame genes, but get moving!
In Sweden obesity among young men increased between five to ten times between 1969 and 2005. If the trend continues, ten percent of the male population will be obese by 2015. (Source: Karolinska Institutet, www.ki.se)

The FTO gene is obesity's main ally, but physical activity reduces its effect in adolescents, according to a study lead by Jonatan Ruiz, a researcher at Karolinska Institutet in Stockholm.

According to findings, a physically active lifestyle during adolescence can play a key role in fighting against obesity in cases that are caused by the FTO (or fat mass gene). In associated studies in Spain, 37% of a cross section of European adolescents did not have a mutation copy of this gene, 47% had a single copy and 16% had two copies.

The results, published in the Archives of Pediatrics and Adolescent Medicine, reveal that the genetic mutation is linked to a higher rate of body mass, fat, and waist circumference. More significantly, its effect disappears when adolescents get proper daily exercise.

"Performing the recommended amount of physical activity can counteract a genetic predisposition to become overweight or obese," Ruiz emphasizes. In this manner, his studies dispute other contentions that claim nothing can be done to avoid genetically influenced obesity, and indicate that modifying lifestyles can cancel the negative effects that some genetic mutations have on health.

"For young people, one hour of sport per day is enough to reduce the potential risk of this genetic mutation", he adds, although participants in the European youth study were only 60% compliant with exercise recommendations.

Source: FECYT - the Spanish Foundation for Science and Technology