Headaches among overweight youngsters also tend to be more frequent, said Andrew D. Hershey, M.D., Ph.D., director of the Headache Center, and a pediatric neurologist at Cincinnati Children's Hospital Medical Center, who presented the data.
He had more bad news: "Kids who are obese are also more likely to have increased disability from their headache." They miss more school and other activities.
But Hershey emphasized he did not find a cause-and-effect relationship. "Obesity doesn't cause you to have a migraine," he said.
His study, believed to be the first of its kind, echoes recent research on adult migraine sufferers.
Other researchers have reported that obese adults who get migraines also get hit harder -- in terms of frequency and severity -- than do thinner people. Exactly why is not known, experts say.
In the new study, Hershey and his colleagues evaluated 466 children, aged 3 to 18, who visited one of seven pediatric headache centers. Most of them -- 91.1 percent -- were diagnosed with migraine headaches; the other 8.9 percent had other types of headaches.
The Headache-Weight Connection
The researchers found that the young headache sufferers were 36 percent more likely to be overweight than children in the general population.
While 21.1 percent of the headache sufferers in the study were overweight, only 15.5 percent of children in the general population are.
Hershey and his colleagues calculated the children and teens' body mass index (BMI) percentile, a measure used to determine whether a child is overweight or at risk for being overweight.
A child with BMI in the 85th percentile to just below the 95th percentile for their age group and sex is termed "at risk of becoming overweight." Those at or above the 95th percentile are considered "overweight."
More Frequent, More Disabling
Hershey's team also asked the youngsters about headache frequency. "Up to 10 percent of kids 5 to 15 will have headaches -- one to two a month," Hershey said. "In our study, we found the average headache frequency was 11 times a month."
That wasn't a surprise, since the children were seeking help at a headache clinic. But Hershey also found that the heavier the child, the more likely he or she was to have frequent headaches.