Obese teenagers can’t seem to stop eating, even when they’ve had their fill. For years, researchers assumed that the problem was largely psychological: Overeating youth had developed an irrational compulsion as a result of stuffing painful emotions.
Recommended treatments have included cognitive therapy, increased exercise and changes in unhealthy dietary habits.
But new research points to another possible obesity cause: brain damage.
A small but pioneering study conducted by Pamela Bertolazzi, a biomedical scientist and Ph.D. student from the University of São Paulo in Brazil, compared the MRI scans of roughly 60 obese and non-obese teens to see what differences might exist in their brain functioning.
The results were stark: In the obese teens, the scans revealed damage to the brain that was connected with inflammatory markers that included leptin, a hormone created by fat cells that helps regulate fat stores and energy levels.
Without the ability to detect the leptin hormone, a person keeps eating despite having adequate amounts of fat stores and fuel for the body.
In a perfect world, the more fat we have, the more leptin we would create and the less we would eat, leading us to lose weight,” says Dr. Dana Hunnes, a senior dietitian at the University of California Los Angeles Medical Center.
But for obesity sufferers, inflammation weakens the brain’s ability to detect leptin to the point where the overeater never receives the “signal” to stop eating.
Because Betolazzi’s study is small and has yet to be peer-reviewed, scholars suggest caution is in order before drawing sweeping conclusions.
In theory, though, it could mean that reducing obesity might be dealt with through new kinds of medical interventions that address inflammation and heal the brain’s capacity to respond to the leptin hormone.
But that assumes that the damage to the brain detected in the MRI scans is actually reversible, which won’t be known until more studies are conducted, Bertolazzi says.
Danelle M. Fisher, a pediatrician and vice-chair of pediatrics at Providence Saint John’s Health Center in Santa Monica, California, says Betolazzi’s findings could alter the focus of future obesity research.
“I think this is going to take researchers in a different direction. It really would explain these [entrenched] patterns of behavior that we see in these teens [that] are having problems [reducing] their obesity levls” she told the magazine Healthline.
In fact, Bertolazzi’s study is not the first or only one to suggest a linkage between obesity and brain functioning.
For example, a study conducted earlier this year in the Netherlands with a much large research sample – 12,000 participants – found that the brain of obesity sufferers tended to contract over time, especially in male sufferers.
Another recent study showed that the brain’s prefrontal cortex — an area that is important for complex thinking, planning, and self-control — is less active in people who tend to overeat, which could lead to weight gain and obesity.
However, Bertolazzi’s study is the first to zero in on the plight of obese teens. Her findings suggest that obesity is inducing brain damage in obesity sufferers at a much earlier age than researchers had previously assumed.
Concern over rising obesity levels in teens is growing. The prevalence of obesity in those aged 12 to 19 has tripled since 1970. The current rate stands at 20 percent – which some medical professionals have described as an “epidemic.”
Early intervention is considered critical to preventing obese children from becoming obese adults.
And obesity is also considered a major risk factor for Type 2 Diabetes, a problem long seen as afflicting adults, but because of rising obesity levels increasingly found in youth.
Some studies have shown that a treatment technique known as Deep Transcranial Magnetic Stimulation (DTMS) that uses magnetic energy to stimulate neurons in specific areas of the brain and has been used to treat depression and substance abuse might also help reduce food cravings.
But no study to date has tested for that possibility, even with adults.
Most of the current behavioral control techniques, while successful in individual cases, have done little to reverse the overall obesity trend.
Bertolazzi says she’s optimistic that her future research will point the way to new medical techniques that focus on reducing the inflammation that disrupts the ability of obesity sufferers to detect when their body is “satiated.”
But in fact, if it turns out that the brain damage they’ve suffered is largely irreversible, treating obesity in children and youth could prove harder than ever.