Children who have migraines are more likely to be overweight than the general population, while overweight kids suffer more disabling migraines than their normal-weight peers, a new study shows.

“If you have two unhealthy conditions, migraine and obesity, you are even more disabled than if you’d had either one,” Dr. Andrew D. Hershey of Cincinnati Children’s Hospital Medical Center, the study’s lead author, told Reuters Health. He reported the findings June 22 at the American Headache Society’s annual meeting in Los Angeles.

Past research has linked obesity to headache and migraine in adults. To investigate if such a connection exists in children and teens, Hershey and his colleagues looked at 440 migraine patients between the ages of 3 and 18 treated at seven specialty headache centers.

While 15.5 percent of the general population of children is obese, 21.1 percent of the headache patients met the criteria for obesity, the researchers found.

In people under 18, obesity is defined as a BMI in the 95th percentile for a person’s age group, meaning it is higher than that of 95 percent of his or her peers. A BMI in the 85th to 95th percentile puts a young person at risk of obesity, while healthy BMI is between the 6th and 85th percentiles.

Using a six-item questionnaire known as the PedMIDAS, Hershey and his team evaluated how disabled the patients were by their headaches. The obese kids’ average scores were 41.9 and at-risk individuals scored 42.9, compared to 33.8 for the group as a whole.

About 10 percent of kids between the ages of 5 to 15 have migraines, Hershey noted. Before adolescence, boys are more likely to have migraines, but about 40 percent outgrow them as they reach adolescence. Girls’ migraine risk rises as they enter puberty, and among adults, women are three times more likely than men to have migraines.

“Obesity probably contributes to the more frequent migraines, meaning if you’re obese you’re less likely to do the healthy habits we talk about - which is eating healthy, exercise and getting good sleep,” Hershey noted. Obesity and migraine can also be a vicious circle, he noted, with headaches making it more difficult for a child to be active.

He and his colleagues are currently following the patients in the study to see if losing weight will reduce the severity of their headaches.