Understanding the link between genetics, exercise, and obesity

A recent study in the Journal of the American Medical Association (JAMA) looked into why some people tend to gain weight more easily than others, even if they exercise regularly. Researchers analysed data from a large group of adults in the United States who provided information about how much they walked each day and their genetic makeup in relation to obesity.

They found that people with a higher genetic risk for obesity were more likely to become obese over time, regardless of how much they exercised. For instance, among those with the highest genetic risk, 43% became obese during the study, compared to only 13% of those with the lowest genetic risk.

Interestingly, the amount of walking someone did also played a role. People who walked more tended to have a lower risk of obesity, but the effect varied depending on their genetic risk. For example, those with a high genetic risk needed to walk about 2,280 more steps each day than average to see the same reduction in their risk of obesity. On the other hand, those with a low genetic risk could get away with walking about 3,660 fewer steps each day and still see the same benefit.

This suggests that genetics and physical activity both influence a person's risk of obesity, and the interaction between the two can vary widely from person to person. So, while staying active is important for everyone, some people may need to be extra diligent about their activity levels to offset their genetic predisposition to obesity.