Interestingly, for the first time we also found that the activation in a part of the brain called the striatum was increased when those with the variant in FTO looked at high-calorie foods, but this depended on which variant of the other gene DRD2 they possessed. The DRD2 variant alters how the dopamine system works in the brain," continued Dr. Goldstone.
These results suggest that part of the reason people with the FTO variant are more likely to have obesity may be because dopamine signals in their brain cause them to feel more reward and craving when presented with high-calorie foods.
"It is possible that people with these particular genetic variants may respond differently to certain treatments for obesity," said Dr. Goldstone.
Possible treatments could include those that change how the brain processes high-calorie foods and how much people like high-calorie foods, and especially those that affect dopamine systems in the brain. This might include hormones from the gut that can act on dopamine brain cells, drugs that alter the way in which dopamine works in the brain, and even specific types of gut surgery for obesity.
"These findings help us better understand the biological basis of behaviors that may predispose some people to overeating high-calorie foods, and hence obesity," said TOS Fellow Leah Whigham, PhD, FTOS, Executive Director of Paso Del Norte Institute for Healthy Living. "It could help us better target treatments for obesity so particular people get the most effective treatment, as individualized approaches to obesity are necessary."