A so-called obesity gene may have more to do with food choices than with metabolism or physical activity.
Researchers are reporting that in the Dec. 11 edition of The New England Journal of Medicine.
The gene researchers studied is called the FTO gene, which is as particular variation of the FTO gene that has been linked to obesity.
That doesn't mean that people with the FTO gene variation are destined for obesity, or that other genes aren't also involved. However, the FTO variant has attracted attention for its ties to obesity.
The new study confirms that connection and goes one step further to ask how the FTO gene influences obesity. For example, does it increase calorie consumption or does it diminish calorie burning?
To learn more, researchers Joanne Cecil, PhD, of Scotland's University of Dundee studied about 2,700 elementary school kids in Scotland.
Cecil's team measured the children's height, weight, and waist and hip circumferences. She also checked the kids' FTO genes, based on saliva samples the students provided.
As expected, the heavier children were more likely to have the FTO gene variant. Their extra weight came from fat mass, not lean tissue.
The groundbreaking part of the study involved a subgroup of 76 students who got their metabolism monitored for 10 days and ate special test meals at the school. The researchers weighed the available food before and after those meals to see how much the kids had eaten.
Those tests showed the FTO variant didn't make for a sluggish metabolism, but it was linked to eating more food, especially high-calorie food, in the test meals.
So the FTO variant seemed to be involved in consumption of calories, not how the body handles those calories, noted Cecil.
Do you have a variant of the FTO gene?
It’s possible that your weight-gain, or inability to maintain weight loss is not your fault and may have more to do with your genes.
Knowing that you have the FTO variant could allow you to make better food choices that address your body’s need for certain types of food that help make you feel full after eating and to avoid the kinds of food that leave you hungry.