Researchers from the University of Maryland School of Medicine and now of the University of Miami say that variations of a particular gene, known as the fat mass and obesity associated (FTO) gene, are widely acknowledged to be linked with a high body mass index.
The variant's effects can be blocked with regular rigorous physical activity according to the study, which is published in the Archives of Internal Medicine.
Researchers studied DNA samples of 704 healthy adults from Amish of Lancaster County, Pa., collected between 2003 and 2007. Participants were fitted with "accelerometers", measuring their precise movements over a period of time. The instrument measured activity level at 15-second intervals.
According to WebMD, the average age of the participants was 44 years and 53 percent were men. Fifty-four percent of the men were overweight and 10 percent were obese. About 64 percent of the women were overweight and 31 percent were obese.
Those who got about three or four hours of moderate physical activity a day and had the FTO gene weighed up to about 15 pounds less on average than the least active people.
The least active group would be comparable to Americans who get little exercise beyond normal activities of daily living. About 30 percent of European populations have such FTO gene variants associated with a greater than 20 percent risk for obesity, the study found.
The authors said it is not clear how the FTO gene influences excess weight, but it is believed to be involved in the function of a protein that may affect how the body regulates food intake.
