More Physical Activity Needed to Cut Risk for Obesity Among Those With Genetic Risk

HealthDay News — The daily step count needed to reduce the risk for obesity varies based on an individual’s genetic risk for higher body mass index (BMI), according to a study published online March 27 in JAMA Network Open.

Evan L. Brittain, MD, from the Vanderbilt University Medical Center in Nashville, Tennessee, and colleagues conducted a retrospective cohort study involving participants from the All of Us Research Program. The association of genetic risk for higher BMI with the level of physical activity needed to reduce incident obesity was examined.

Overall, 3124 participants met the inclusion criteria; 3051 had available data. The researchers found that the incidence of obesity increased from 13 to 43% in the lowest and highest quartiles of polygenic risk score (PRS) for BMI during the study period. When comparing the 75th and 25th percentiles, there was an 81% increase in obesity risk for the BMI PRS, while a 43% reduction was seen in mean step count. To have a comparable risk for obesity, individuals with a PRS in the 75th percentile would need to walk a mean of 2280 more steps per day than those at the 50th percentile. To have a comparable risk for obesity as those at the 25th percentile of BMI, those at the 75th percentile would need to walk an additional 3460; 4430; 5380; and 6350 steps/day with a baseline BMI of 22, 24, 26, and 28kg/m², respectively.

“These results have important clinical and public health implications and may offer a novel strategy for addressing the obesity epidemic by informing activity recommendations that incorporate genetic information,” the authors write.

One author received a gift from Google LLC; a second author disclosed ties to the biotechnology industry.

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