Impulsivity, Hyperactivity Linked to Higher Body Mass Index in Study

Oct. 29, 2010 — Having ADHD symptoms in childhood is associated with an increased risk for obesity later in life, a new study suggests.

Symptoms such as problems with impulse control and hyperactivity were strongly linked to obesity in young adulthood, even among children without a diagnosis of ADHD, Duke University Medical Center researchers report.

The study is not the first to suggest an association between ADHD and obesity, but it is the first to examine the role of specific ADHD-related symptoms in weight control.

“Symptoms such as hyperactivity and [problems with] impulse control were associated with higher body mass index (BMI) in adulthood, even when there was no diagnosis of ADHD,” study co-author and Duke ADHD Program director Scott Kollins, PhD, tells WebMD.

ADHD and Obesity

The investigation, published in the International Journal of Obesity, included almost 15,200 children enrolled in a nationally representative adolescent health study followed from 1995 until 2009.

After controlling for other obesity risk factors, the researchers found that children with the most hyperactivity and impulsivity symptoms also had the highest risk for obesity in early adulthood.

The more symptoms children exhibited the greater their later obesity risk.

Although it is not clear from the study how these symptoms influence weight, the researchers speculate that impulse control issues may be more to blame than hyperactivity.

“Self-regulation and impulse control problems are hallmarks of ADHD and overeating,” Kollins says. “Kids with these issues may not be able to resist the urge to eat five cookies instead of two and they may ignore signals telling them they are full.”

It is well recognized that children with ADHD are at increased risk for substance abuse and addiction later in life.

Obesity researcher Caroline Davis, PhD, of Toronto’s York University, believes this propensity for addiction explains why kids with symptoms of ADHD may be more likely to overeat.

Researcher: ‘Food Is a Drug’

Davis tells WebMD that foods that are high in fat, sugar, and salt act on the brain’s reward system in the same way addictive drugs do.

Davis says it is no coincidence that the first studies linking ADHD to obesity were published just over a decade ago.

“It is my personal feeling that this link is pretty new,” she says. “The food environment has changed dramatically just within the last several decades. we now have a whole generation that has grown up on these highly addictive foods.”

Duke assistant professor of community and family medicine Bernard Fuemmeler, PhD, says findings from the newly published study may be useful for understanding ADHD and obesity.

“Clinicians need to be aware that children who exhibit symptoms of ADHD may have difficulty managing their weight as they get older,” he says. “For these children, working on behavioral control strategies may reduce this risk.”