ADHD, or attention-deficit/hyperactivity disorder, has been the subject of much debate, but researchers know one thing for sure – it affects everyone differently. According to a report from CBS News, a recent study suggests that the disorder’s effects may be even split along gender lines.

Scientists at the Mayo Clinic linked ADHD to obesity in a 1,000-person study, but the data revealed a strange pattern. They found that girls with the disorder were nearly twice as likely to be obese during childhood and adolescence than girls without ADHD.

Even after controlling for factors like medications and activity levels, the researchers found no such association in the male section of the study. “There are a couple of biological mechanisms that underlie both obesity and ADHD,” stated Dr. Seema Kumar, a pediatrician and scientist at the Mayo Clinic Children’s Research Center.

“Girl with ADHD may not be able to control their eating and may end up overeating. Because kids with ADHD don’t have impulse control, it may also play a role in this,” Kumar said.

Dr. Kumar elaborated on some of the differences between ADHD in boys and girls, explaining that boys with the disorder are often hyperactive and burn a lot of energy. This could partially explain the distribution of obese children with ADHD along gender lines observed in the study, but little evidence exists suggesting that boys with ADHD are more hyperactive than girls.

The scientists also hypothesized that trouble sleeping could contribute to the higher rates of obesity in girls with ADHD, but fell short of an obvious explanation for the association. There are a number of factors associated with weight gain, and it’s not a given that children suffering from ADHD will gain weight.

The scientists reiterated that the study’s findings only presented a link, and not ADHD as a cause for childhood obesity. Diet and exercise remain two of the most important factors associated with weight gain, and parents and caretakers of children with ADHD should remain aware of the possibility of unhealthy habits.

A press release from the Mayo Clinic describing the details of the recent study can be found here.