WEDNESDAY, Sept. 11 (HealthDay News) -- Obese people may be at higher risk for episodic migraines, a new study suggests.

Episodic migraines -- the more common type of migraine -- occur 14 days or fewer per month, while chronic migraines occur at least 15 days per month.

Migraines involve intense pulsing or throbbing pain in one area of the head, according to the American Academy of Neurology. Symptoms can include nausea, vomiting and sensitivity to light and sound. Migraines affect more than 10 percent of the population.

In the study of more than 3,800 adults, those with a high body-mass index (BMI) -- a measure of body fat determined using height and weight -- were 81 percent more likely to have episodic migraines than those with a lower BMI. This was particularly true among women, whites and those under the age of 50.

The cross-sectional study doesn't prove that obesity causes episodic migraines, but it does demonstrate that people who are obese have an increased risk of having more of them, even low-frequency ones, said lead author Dr. Barbara Lee Peterlin, director of headache research at Johns Hopkins University School of Medicine, in Baltimore.

"These results suggest that doctors should promote healthy lifestyle choices for diet and exercise in people with episodic migraine," Peterlin said in a statement. "More research is needed to evaluate whether weight-loss programs can be helpful in overweight and obese people with episodic migraine."

The study was published in the Sept. 11 issue of the journal Neurology. The researchers also presented the findings in June at the International Headache Congress in Boston.

Dr. Gretchen Tietjen, director of the headache treatment and research program at the University of Toledo, in Ohio, said she found the findings interesting because previous studies had looked for connections between obesity and chronic migraines.

"That the researchers were able to show an association between obesity and episodic migraine lends more credence to some of the earlier studies that found similar things," she said.

She pointed out, however, that it still isn't known which came first -- the obesity or the migraine. There are many possible scenarios, Tietjen said. "Maybe the person had the migraines first and then started taking medications like amitriptyline or valproic acid," she said. "Those medications are associated with weight gain."