A gene that affects body mass index (BMI) may increase the risk of obesity through sedentary behavior according to a new study by researchers at the University of Arizona Mel and Enid Zuckerman College of Public Health.

The findings, published online October 22 in the International Journal of Obesity, suggests that FTO, the fat mass and obesity associated gene, may affect obesity through the behavior of sitting.

Lead researcher Yann Klimentidis, PhD, an assistant professor who studies genetic epidemiology at the UA Zuckerman College of Public Health, said the research team looked at the FTO gene because it’s the strongest known genetic contributor to obesity.

Past research has found that this particular gene may be modulated by physical activity. “We know there are interactions between your genetic background and your lifestyle. If you are active, the effect of this gene may be reduced. In general, your genetic profile may determine the type and duration of exercise needed to lose weight.”

Dr. Klimentidis and colleagues looked at the connection between FTO and time spent sitting (TSS) or inactivity. “We asked the question: does this gene affect TSS, and subsequently BMI? We know FTO is associated with high BMI. What we don’t know is how it may increase BMI. This study gave us a clue about how FTO might increase BMI.

Using two large, long-term studies, the Framingham Heart Study and the Women’s Health Initiative, the researchers examined whether a common variant of a gene called FTO was related to self-reported time spent sitting. The results showed a significant positive association between the BMI-increasing FTO allele and TSS, after adjusting for potential confounders such as BMI and physical activity.

Further research into the intersection of genetics, sedentary behavior and obesity-related outcomes is warranted.

Source:  bit.ly/1jE6Euk International Journal of Obesity, online October 22, 2015