New research published in this week’s PLoS Medicine reveals that by living a physically active lifestyle, the genetic predisposition to obesity caused by the ‘fat mass and obesity associated’ (FTO) gene can be significantly reduced. The large international collaboration was led by Ruth Loos from the Medical Research Council Epidemiology Unit in Cambridge, UK, and showed that the effect of the FTO gene on obesity risk is nearly 30% weaker among physically active adults compared with those who are physically inactive.

This finding challenges the common excuse of “obesity is in my genes’ and relays an important public health message to care professionals and the general public alike that obesity is indeed amenable to lifestyle changes. The study proved that those genetically predisposed were able to reduce their risk of becoming obese by being physically active.

Following a comprehensive literature search, the researchers invited all scientists who had previously reported on the FTO gene to participate in their study. The researchers examined data from more than 218,000 adults with extensive and innovative methodology to prove that carrying a copy of the FTO gene generally increases the risk of becoming obese, however, the FTO gene’s effect on obesity was 27% less pronounced in physically active people (1.22 fold) compared with those who were physically not active (1.30 fold).

The researchers conclude:

“Our findings are highly relevant to public health. They emphasize that physical activity is an effective way of controlling body weight, particularly in individuals with a genetic predisposition towards obesity. Thus, they contrast with the determinist view held by many that genetic influences are unmodifiable.” The researchers believe that these findings will bring them a step closer to more personalized healthcare by identifying people who will benefit most from a targeted treatment.

Dr. J. Lennert Veerman from the School of Population Health at the University of Queensland in Australia writes in an accompanying comment:

“Testing for genetic traits that are associated with obesity makes no difference in the advice to overweight persons: increased physical activity and a healthy diet are indicated regardless of the genes. A focus on individual genetic traits is a mere distraction and reinforces the popular view of obesity as a problem that individuals have to deal with, rather than one that requires societal action.”

Written by: Petra Rattue