The level of physical activity required to prevent obesity depends on an individual's genetic risk, a new study has found.
The daily step count required for a person with a higher genetic risk of obesity is more than those with moderate or low genetic risk, according to the study published in Jama Network.
To estimate the link between the genetic risk of higher body mass index (BMI) and the level of physical activity needed to reduce incident obesity, researchers used genetic data from the All of Us Research Program (AoURP). Genetic risk of higher BMI was measured as polygenic risk score (PRS) and physical activity was measured in terms of daily step counts.
The results showed that higher PRS and lower daily step counts were each independently associated with an increased risk for obesity.
Individuals in the 75th percentile of PRS would need to walk approximately 2,280 extra steps daily to make their risk comparable to the 50th percentile. Meanwhile, those in the 25th percentile could manage with about 3,660 fewer steps.
"Your genetics are not your destiny with regards to obesity risk. We showed that even high genetic risk for obesity can be overcome with higher levels of activity, which I think is an empowering message," said lead author, Evan Brittain, of Vanderbilt University Medical Center in Nashville, Tennessee.
However, most physical activity guidelines follow a "one size fits all" approach without considering the genetic risk. "One of the central messages [of this study] is that risk for obesity and how much activity is needed to prevent it varies dramatically across the genetic spectrum. Therefore, public health guidelines likely underestimate the amount of activity needed to prevent obesity in individuals with higher genetic risk," Brittain said.
The researchers hope their findings will bring people closer to a future where activity recommendations are personalized to individuals based on their genetic background.
"Patients and their doctors are increasingly gaining access to genetic information that may have clinical importance. In the future, I suspect doctors will be able to take advantage of this information to provide more personalized 'prescriptions' for activity to prevent obesity and other chronic diseases associated with sedentary behavior," Brittain explained.
