Tokyo, Dec 23 (IANS): If you are unable to control your urge from snacking over chips, ice creams or chocolates, blame it on a gene. A team of Japanese researchers has identified the role a gene plays in stimulating the brain, causing people to overeat.

Recently, it became clear that a gene called CREB-Regulated Transcription Coactivator 1 (CRTC1) is associated with obesity in humans. When CRTC1 is deleted in mice, they become obese, indicating that functioning CRTC1 suppresses obesity.

However, since CRTC1 is expressed in all neurons in the brain, the specific neurons responsible for suppressing obesity and the mechanism present in those neurons remained unknown, according to the study published in the FASEB Journal.

To understand the mechanism by which CRTC1 suppresses obesity, a research group led by associate professor Shigenobu Matsumura from Osaka Metropolitan University focused on neurons expressing the melanocortin-4 receptor (MC4R).

They hypothesized that CRTC1 expression in MC4R-expressing neurons suppressed obesity because mutations in the MC4R gene are known to cause obesity.

When fed a standard diet, the mice without CRTC1 in MC4R-expressing neurons showed no changes in body weight compared to control mice. However, when the CRTC1-deficient mice were raised on a high-fat diet, they overate, then became significantly more obese than the control mice and developed diabetes.

High-calorie foods -- high in fat, oil and sugar -- can taste good but often cause overeating, leading to obesity and major health problems.

"This study has revealed the role that the CRTC1 gene plays in the brain, and part of the mechanism that stops us from overeating high-calorie, fatty, and sugary foods," said Matsumura.

"We hope this will lead to a better understanding of what causes people to overeat," Matsumura added.