Researchers have found genes that are associated with night-eating syndrome.

That midnight craving for food might have a genetic basis. According to researchers at Salk Institute for Biological Studies, mutations in a gene - PER1 - could lead to overeating at night, at least in mice models.

The team found a pair of genes that keep eating timings in sync with daily sleep rhythms. When these genes are mutated, the synchrony breaks, which leads to disrupted eating schedule.

"We really never expected that we would be able to decouple the sleep-wake cycle and the eating cycle, especially with a simple mutation," says senior study author Satchidananda Panda, an associate professor in Salk's Regulatory Biology Laboratory. "It opens up a whole lot of future questions about how these cycles are regulated."

This is the first time that researchers have directly linked PER1 to night-eating syndrome. People with NES tend to wake up in the middle of the night to eat, which leads to altered sleep cycle and weight gain. Research has previously linked NES to mental disorders.

For the study, researchers bred mice with two genes - PER 1 and PER 2, which has earlier been associated with sleep disorder.

Researchers found that mutation in PER 2 genes was associated with sleeping problems. However, mice with PER 1 mutation had no problem in sleep patterns. Instead, these mice tended to eat more food than the others, Medical Daily reported.

"In the mice without PER1, there was no obvious defect in their sleep-wake cycles," Panda said in a news release. "Instead, when we looked at their metabolism, we suddenly saw drastic changes."

The researchers hypothesized that both genes keep each other in check to maintain a normal sleeping-eating cycle. Mutation in either gene leads to sleep or feeding disorders.

"For a long time, people discounted night-eating syndrome as not real," said Panda. "These results in mice suggest that it could actually be a genetic basis for the syndrome."

Note that the study was conducted on mice models. Whether or not the genes affect sleep-eat cycle in humans is not known yet.

The study was funded by the National Institutes of Health, USA, the Ministry of Science and Technology of China, the National Science Foundation of China and is published in the journal Cell Reports.