The reason we reach for chocolates and sweet treats when we’re stressed may have been uncovered by scientists at Japan’s National Institute for Physiological Sciences.

The researchers identified the specific neurons that cause a change from a preference for a high fat diet (HFD) when mice are in a normal state to a high-carbohydrate diet (HCD) when they are under stress.

“The finding could unravel the mechanism of why we crave sugar when we’re stressed,” said Yasuhiko Minokoshi, a member of the team and a professor of neuroendocrinology at the institute.

The results were published in the U.S. scientific journal Cell Reports on Jan. 17.

The study focused on an enzyme which becomes activated after detecting a lack of energy in the body and regulates metabolism to recover energy.

In their experiments, the team members activated the enzyme in the rodents’ brains and found that it induced the activation of a subset of corticotropin-releasing hormone (CRH), positive neurons in the hypothalamus which are activated by stress.

When their CRH neurons were activated, the intake of high-fat food by mice dropped to one-third of that of their normal state, while it led to a 9.5-fold increase in their intake of high-carbohydrate food.

On the other hand, when scientists curbed activities of CRH neurons in mice, it didn’t increase the amount of carbohydrates they ingested, but they ate plenty of high-fat food.

The findings could have implications for human behavior, too.

“Dysregulation of food selection behavior is associated with stressful life events in humans,” said Minokoshi.

“This study will contribute to the better understanding of the molecular mechanisms underlying the effects of stress and obesity in food selection behavior,” he added.