Overweight children who have headaches are likely to find them more disabling than do leaner headache sufferers, new research shows.

However, heavy children who lost weight while undergoing headache treatment showed a much greater reduction in headache frequency than their peers whose weight remained stable or increased, Dr. Andrew D. Hershey and his colleagues found.

"Those kids that are overweight and lose weight or normalize their BMI have a greater improvement than those that don't, and in fact those that gain weight actually get a little bit worse," Hershey, at Cincinnati Children's Hospital Medical Center, explained in an interview.

There is evidence linking obesity and chronic headache in adults, the researchers note in their report ion the medical journal Headache, but there is less information on how excess weight might influence headaches in young people.

To investigate, Hershey and his team followed 913 patients ranging in age from 3 to 18 who needed treatment for headache. Most were diagnosed with migraine, while some had tension-type headaches. Among the group, 17.5 percent were overweight.

At the study's outset, the children with higher body mass indexes had headaches more often and were more disabled by their headaches. Three months after treatment began, the researchers found that patients who showed greater reduction in their BMI also showed a greater drop in headache frequency. They saw a similar relationship after six months of treatment.

The findings can't determine whether being overweight causes headaches, or vice versa, Hershey said.

Nevertheless, he added, "The same things that make obesity worse are the same things that make headaches worse." So, eating healthily, exercising and getting enough sleep — all standard recommendations for headache sufferers — can also help people maintain a healthy weight.