BEIJING Jan. 10 (Xinhuanet) -- Keeping a healthy diet may help children with attention deficit hyperactivity disorder (ADHD) in their treatment, a new study revealed.

The study was published Monday in the American medical journal Pediatrics.

After analyzing 70 previous study on the ADHD children, the researchers from Children's Memorial Hospital in Chicago suggested foods such as fish, vegetables, fruit and whole grains which contain heavy fiber, folate and omega-3 fatty acids can help decrease the hyperactivity symptom.

Though typical "Western-style" diet that's high in fat, salt and refined sugars should be avoided in eating. However, diet chenge cannot replace the medicinal treatment, the researchers warned.

"It (changing diet) is usually not a first choice," said study author Dr. J. Gordon Millichap.

There are at least 5.4 million children aged 4 to 17 in the world have been diagnosed with ADHD. And the conventional therapies are medical treatment and behavior changes.