NPR for North Texas
Play Live Radio
Next Up:
0:00 0:00
Available On Air Stations

Study Suggests Kids' Obesity May Be Linked To Brain Size

Stock Photo
A study found obese children had less volume in the part of the brain that regulates impulse control and planning than kids of normal weight.

A new study suggests there is a tie between brain differences and obesity. Brain scans on nearly 3,200 children found those who were overweight had slightly less volume in a part of the brain that controls “executive functions.”

Dr. Cristina Wohlgehagen, a neurologist with Texas Health Presbyterian Hospital Dallas, explained what executive functions are, and what the results of the study say about the need for healthier lifestyle choices.

“I hope that what this study does is destigmatize obesity, and that people see it as a chronic condition that is multifactorial, and that affects multiple organ systems — including the brain," Wohlgehagen said. "So we need to treat it in an integrative way.”


What researchers wanted to know:

In kids who are overweight, they wanted to find out a couple of things:

  • Does their brain structure look different or is it about average?
  • Is there an association between the testing scores and an increase in BMI? And if there is, can you predict how the overweight student will perform on their executive function test based on the size of their brain.

What researchers found:

They found the higher the weight, the lower the critical thickness of brain. The higher the weight, the lower the scores on the executive function tests.

What are executive functions:

Those are the things that help us to make decisions about what to do next. I.Q. measures your intelligence. This is more about how you direct that intelligence. How do you go about your day — say, planning what foods you’re going to eat, which might be important in someone who is obese. How do you stop an impulse from coming out.

The problem:

The brain continues to grow until we’re 23. The front of our brain is where the executive function is. If we’re saying that it’s still developing and it has shrunk, then what does this mean? Are we changing the development of theses children’s brain? How does obesity play a role in that? But, with a cross-sectional study, you can only say association, not causation. There’s no chicken or egg here.

Hope in Neuroplasticity:

We’re finding that the brain is changeable, and that we can do lifestyle modifications that you could implement today. That would include losing weight.

But you can’t just lose weight, it has to be a healthy lifestyle modification: better choices of food, exercise, no smoking, drinking water. There’s good evidence in adults that these lifestyle modifications can have a positive impact on the brain. Now we’re seeing in this study that this may also apply in children. The question mark is whether it’s affecting the brain or developing it.


Study in JAMA Pediatrics

ABC News: Brain differences may be tied to obesity, kids' study says

Science Times: There is a Link Between Obesity and Brain Functions, Study Finds

Obesity and the growing brain

Answers have been edited for brevity and clarity.

Sam Baker is KERA's senior editor and local host for Morning Edition. The native of Beaumont, Texas, also edits and produces radio commentaries and Vital Signs, a series that's part of the station's Breakthroughs initiative. He also was the longtime host of KERA 13’s Emmy Award-winning public affairs program On the Record. He also won an Emmy in 2008 for KERA’s Sharing the Power: A Voter’s Voice Special, and has earned honors from the Associated Press and the Public Radio News Directors Inc.