Researchers in Great Britain studied 12 genetic variants known to increase the risk of obesity and tracked the physical activity levels of 20,430 people.

They created a genetic summary score to quantify a person’s risk of obesity and then examined whether an active life could reduce the genetic influence.

Findings: Physical activity can reduce the genetic tendency toward obesity by 40%, according to the research, reported Tuesday in PLoS Medicine.

“Our findings challenge the popular myth that obesity is unavoidable if it runs in the family,” says senior researcher Ruth Loos of Great Britain’s Medical Research Council in Cambridge. “We see this as a hopeful message.”

You can get the benefits without running marathons, she says. You can walk the dog, bike to work or take the stairs: “Being active about 30 minutes a day is a good start in reducing the effects of the genes.”.

From USA Today.