27 April 2017

Physical activity helps to counteract weight gain from obesity-causing gene variant

OBESITY

With people consuming more calories and being less physically active, the world has witnessed an obesity epidemic, but not everyone is gaining weight. New research from the Metabolism Center shows that physical activity can reduce the weight-gaining effects of the genetic variant that carries the greatest risk of obesity.

Previous studies suggest that a person’s susceptibility to becoming obese can be reduced by physical activity. To see how physical activity and genetic variants related to obesity interact to affect weight gain, Associate Professor Tuomas Kilpeläinen and colleagues performed genome-wide interaction meta-analyses using more than 200,000 individuals.

The study has just been published in the scientific journal PLOS Genetics.

“We studied more than 200,000 adults who were asked about their physical activity habits and their genes were evaluated. Among the around 2.5 million genetic variants that we tested for each participant, we found that there is a relationship between the strongest known obesity risk gene FTO and physical activity. The effect of the FTO risk is nearly 30% weaker in physically active than in physically inactive participants, which means that those wired to be heavier may benefit more by working out than their counterparts,” says Kilpeläinen.

The meta-analyses confirm previous findings that physical activity reduces the effect of the FTO gene, but the underlying cause of this interaction is still unknown. The scientists suspect that physical activity may affect other genes related to obesity, but to identify these smaller effects, researchers will require larger groups of subjects and highly precise measurements.

From a practical standpoint, the findings suggest that physical activity is still vital, even when obesity appears to be predetermined in one’s genes, and could be most beneficial for those who have the hardest time keeping weight off.

“Moreover, our study revealed 11 completely new obesity genes, suggesting that in future studies, accounting for physical activity and other important lifestyle factors could boost the search new obesity genes,” concludes Kilpeläinen.