Medics find out who doesn't get enough 10,000 steps a day to reduce their risk of obesity
According to the WHO, more than one billion people in the world today are obese. Studies have repeatedly shown that this is a complex disease linked in some to genetics. Now scientists have found that people with genetic prerequisites for excess body fat need a much more active lifestyle than usual to prevent obesity from developing.
The new study, published in the journal JAMA Network Open, was conducted by experts at Vanderbilt University Medical Center (Tennessee, USA). As part of it, scientists compared data on physical activity with the results of clinical and genetic analyses of more than 3,000 people who participated in the American health research project All of Us Research Program from May 2018 to July 2022. By applying statistical analysis techniques to this information, health professionals traced the link between a genetic propensity for obesity and the amount of physical activity needed for a reduced risk of obesity.
The sample consisted of participants of European descent who used personal activity trackers and were not obese within the first six months of tracking. Among them, 73% (2216) were women and 27% (835) were men. Participants ranged in age from 36 to almost 63 years (mean 52.7 years), and ethnicity was predominantly white (95%).
During the observation period, which averaged over five years, participants took 8,326 steps per day (median). The researchers found that obesity was more likely to develop in people with a strong genetic predisposition to overweight, which was reflected in high scores on the polygenic risk scale of elevated body mass index (BMI PRS). The incidence in these participants was as high as 43% compared to 13% in the group with low scores on this scale.
The doctors calculated that the most prone to obesity would need to walk an average of 2,280 more steps per day, that is, more than 11,000 steps, to bring their risk of obesity down to the level of participants in the group with an average tendency to overweight.
In addition, the analysis showed that the higher the initial BMI in people with pronounced genetic preconditions for fullness, the more effort is needed to reduce the risk of obesity.
Recall that the body mass index, or BMI (body mass index, BMI), is calculated using the formula weight divided by the square of height in meters. It allows you to assess how much a person's weight corresponds to his or her height. A BMI of 18.5 to 24.9 is considered healthy. If the indicator is more than 25, it speaks of overweight, and the level above 30 refers to obesity.
So, in order to equal the risk of obesity with participants in the group with a low predisposition to this condition, people with a strong genetic predisposition to excess body fat and a baseline BMI of 22 would need to walk 3,460 steps per day more than the reported level of 8,326 steps. A baseline BMI of 24, 26 or 28 required an additional 4,430, 5,380 or 6,350 steps per day, the researchers calculated. At the highest point, that's more than 14,500 steps, or 11-plus kilometers.
How achievable that is is a separate question. Of course, for a motivated person, the task is quite feasible. The problem is that in reality, most people do not have the time, and desire for such a long walk, and daily. Nevertheless, the scientists noted that their results are important because they point to the need to take genetic characteristics into account when making recommendations on physical activity.