Childhood obesity may not be the result of kids or parents lacking will power, a new study suggests, but it might have something to do with how their brains work. Using functional magnetic resonance imaging (fMRI), researchers found that children with the greatest obesity risk displayed the least neural activity in brain regions responsible for self-regulation. The findings suggest that the urge to eat may be somewhat hardwired into our brains.
But that doesn’t mean we can’t fix it. “The important thing about brain function, unlike genes, is that it is amenable to change,” coauthor on the study Susan Carnell of Johns Hopkins University told Fatherly. “If we can understand how children’s brains might be leading them to gain excess weight, we may be able to intervene.”
In the United States, 35 percent of adolescents are overweight and 21 percent are obese. It’s easy to blame parents for overindulging kids, or not being strict enough with their diets, but past studies have shown that parent-led interventions seldom curb obesity among kids. In fact, tougher parenting has been shown increase the risk of over-eating. Additional research shows that genetics likely plays a significant role in how a child’s appetite develops, which is what prompted Carnell to ask whether neuroscience is also a piece of the childhood obesity puzzle.
For the study, Carnell and her colleagues divided a small sample of 36 adolescents into three groups— 10 were overweight or obese, 16 were lean but considered at high risk for obesity because they had overweight mothers, and 10 were lean and low risk. While hooked up to fMRI, kids were shown images of high-calorie foods like cheeseburgers and hot fudge sundaes, alongside healthier options, and a handful of inedible controls. After that, all of the children were led to a buffet of junk food and healthy food, and told they could eat whatever they wanted. (Best. Study. Ever.)
As expected, overweight kids were observed eating more unhealthy foods during the buffet portion of the experiment. But when Carnell and colleagues analyzed their brain scans, they found that the lean and low-risk kids displayed the most brain activity in response to high-calorie foods, specifically in a part of the brain associated with self-regulation. Obese children and children at risk of obesity, on the other hand, displayed very little activity in this brain region.
“These findings have really made me flip my thinking,” Carnell says. ”In a way, I am now more interested in asking the question—what is it about the brains of lean, low-risk teenagers that are keeping them lean?”
Given the small sample, Carnell and her team cannot answer this question definitively. But she’s currently working on a larger, more detailed study to expand on her preliminary results. In the meantime the practical takeaway is that, if childhood obesity is neurologically rooted in self-regulation, then it’s more important than ever for parents to model good self-regulation skills. This could be a game-changer for children who believe obesity is their own fault, and give some clues as to a neurological reason why some people just seem to stay lean, even in a culture built around excess.
“When you think about it,” Carnell says. “Given our modern food environment, which is saturated in highly-palatable, easily available, energy-dense foods, it’s actually quite surprising that not more of us are obese.”