People at higher genetic risk of obesity require increased workout intensity: Study

Individuals with a higher genetic predisposition to obesity may find that they need to put in more effort during workouts to achieve similar results because genetic factors can influence their metabolism, fat storage, and energy expenditure, making it more challenging to maintain a healthy weight through exercise alone.

“Physical activity guidelines do not account for individual differences. Genetic background contributes to the amount of physical activity needed to mitigate obesity. The higher the genetic risk, the more steps needed per day.” said senior author Douglas Ruderfer, PhD, associate professor of Medicine, Division of Genetic Medicine, and director of the Center for Digital Genomic Medicine at VUMC.

The study included 3,124 middle-aged participants without obesity who owned a Fitbit device and walked an average of 8,326 steps per day for a median of more than 5 years. The data revealed that the incidence of obesity over the study period increased from 13% to 43% in the lowest and highest polygenic risk score groups. Individuals with a polygenic risk score in the 75th percentile were required to walk an average of 2,280 more steps per day (a total of 11,020 steps per day) than those in the 50th percentile to have a comparable risk of obesity. People with a baseline BMI of 22, 24, 26 and 28 who were in the 75th percentile of polygenic risk score were required to walk an additional 3,460, 4,430, 5,380 and 6,350 steps per day, respectively, to have a comparable risk of obesity to persons in the 25th percentile.

“I think it is intuitive that individuals who have a higher genetic risk of obesity might need to have more physical activity to reduce that risk, but what is new and important from this study is that we were able to put a number on the amount of activity needed to reduce the risk,” said lead author Evan Brittain, MD, associate professor of Medicine in the Division of Cardiovascular Medicine at VUMC and lead investigator in Digital Health for the All of Us Research Program Data and Research Center. “We would like to test whether knowledge of one’s genetic risk for obesity actually has an impact on their behaviour. I think these findings could be empowering for patients because the current physical activity guidelines take a one-size-fits-all approach, and what we learned is that depending on your genetic risk, the guidelines may underestimate the amount of activity needed to reduce your risk of obesity.”

Reference: Physical Activity and Incident Obesity Across the Spectrum of Obesity Genetic Risk; Journal: JAMA Network Open