Being overweight has been linked to changes in an area of the brain involved in memory, emotions and appetite, according to a recent study.

Researchers at SUNY Downstate Medical Center in New York found that excess weight could be related to reduced levels of the molecule N-acetyl-aspartate (NAA) which reflects brain cell health in the hippocampus, according to a press release.

Researchers said this is the first human research documenting the association of NAA with body weight.

"The relevance of the finding is that being overweight is associated with specific changes in a part of the brain that is crucial to memory formation and emotions, and probably to appetite," Jeremy Coplan, leader of the study and professor of psychiatry at the university, said in a statement.

Normal weight is defined as a BMI of 18.5-24.9, overweight between 25 and 29.9, and obesity at a BMI of 30 or greater.

For the study, researchers used magnetic resonance spectroscopy, a non-invasive magnetic resonance imaging (MRI) application, to visualize the molecule. They saw that overweight study participants exhibited lower levels of NAA in the hippocampus than normal weight subjects.  Researchers said this effect was independent of age, sex and psychiatric diagnosis.

In their study, researchers said the hippocampus' role in appetite control is not well known.

"Whether low NAA is a consequence of being overweight, causes being overweight, or a combination of both remains to be determined," Coplan said. "Future studies are planned to focus on whether weight loss leads to an increase in NAA."

The results of the study were published in Neuroimage: Clinical.