Three to four hours of exercise trump the FTO obesity gene, according to a recent study of Amish men:
Researchers focused their study on a group of 704 Old Order Amish men and women in Lancaster County, Pennsylvania, a religious group whose members often do not drive cars or have electricity in their homes.Snitker said the group offered a unique mix of activity levels, with some farmers in the community still using horse-drawn plows while others holding more conventional jobs, including factory work.
He and colleague Evadnie Rampersaud of the University of Miami were looking to see if physical activity in this group might offset the effects of the fat mass and obesity associated with the FTO gene, found in more than half of all people of European descent.
People with two copies of the FTO gene on average weigh nearly 7 pounds (3 kg) more and are about 70 percent more likely to be obese than those who do not have the gene.
The volunteers wore a device called an accelerometer to track motion for a week.
The researchers compared body mass index or BMI, a measure of weight to height, and found those who were less active and had the FTO gene variant were significantly more likely to be overweight or obese.
But among the most physically active, the FTO gene made no difference.
Snitker said the study gives some perspective on how the obesity epidemic has evolved, as modern conveniences have reduced the need and opportunity for physical activity.
People in the most physically active group expended about 900 more calories per day than the low-activity group. That would equal three to four hours of moderately intense physical activity such as brisk walking, house cleaning or gardening.
“We probably carry genes that 150 years ago were not risk factors for obesity, but because of changes in our environment, they become liabilities,” he said.