What's the Latest Development?

British researcher have found that people genetically predisposed to having weight problems can counter the influence of their D.N.A. by doing even moderate amounts of exercise. Scientists at the Institute of Metabolic Science in the U.K. reported that "having a copy of an F.T.O. variation [a gene associated with obesity] increased an adult's risk of obesity by about 30%. But if that person exercised, it cut the risk to 22%—a 27% drop in risk." Kinds of exercise included walking the dog, riding a bike or gardening. 

What's the Big Idea?

Scientists are still not certain how exercise affects obesity-related genes but they think physical activity might trigger changes in gene expression, suppressing genes linked to obesity while activating health-promoting ones. Ruth Loos, who led the research, says: "This should convince people who think that their weight is in their genes, and sit back and say they can't do anything about it, that they can so something about it." Regardless of whether you inherited obesity-related genes, exercise improves physical and mental health.