NATIONWIDE -- A meta-analysis of 15 genetic studies, covering more than 90,000 patients, found six new genetic variants associated with an increased body mass index (BMI) and risk of obesity.

Five of those genes are active in the brain, which means that obesity risk could be related more to behavior than to metabolism, researchers suggest.

The study was published in Nature Genetics and included authors from more than 60 facilities. Study authors note that until 2007, scientists had not uncovered any genetic links to obesity. However, the links that have been discovered since then are likely to influence brain function.