Researchers have previously identified a gene—FTO—that seems to predispose individuals to obesity. A recent study published in PLoS Medicine (2011; 8 [11], e1001116) contends that exercise can reduce the effects of the FTO gene. The researchers analyzed 45 studies from Europe, North America and Asia that encompassed data from more than 218,000 adults along with a meta-study of 19,286 children. The data included body mass index, waist circumference, body fat percentage, self-reported levels of physical activity and genotypes. In analyzing the data, the researchers discovered that physical activity attenuated the influence of FTO on body mass index and obesity.

“The association of the FTO variant with BMI and with the odds of obesity was reduced by approximately 30% in physically active compared to inactive adults,” the study authors explained. “We also found an interaction effect on the odds of overweight and on waist circumference and body fat percentage.” This result held true only for adults. There appeared to be no interaction between FTO and physical activity in the children studied.

The bottom line? “Our findings are highly relevant to public health,” the authors declared. “They emphasize that physical activity is a particularly effective way of controlling body weight in individuals with a genetic predisposition toward obesity and thus [the findings] contrast with the determinist view held by many that genetic influences are unmodifiable.”

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