Night-eating syndrome linked to faulty gene

An irresistible urge to wake up at night and eat has been linked to a faulty gene according to a new research.

The study, published in Cell Reports, discovered that night-eating syndrome, or the inability to avoid feeling hungry at night, is linked to a faulty gene PER1.

In some people it can disrupt sleep, lead to over-eating and weight gain. Symptoms include walking in the night and being unable to go back to sleep without eating.

Scientists believe both PER1 and PER2 work in synchronisation with each other and are responsible for sleeping and eating cycles in humans. But a mutation of PER1 can break the link coordination, leading to an urge to eat at night.

The discovery was made by inducing the two genes in mice. When PER2 was defective, the mice dozed off earlier than usual, as expected. But de-activating PER1 made them want to eat when they should have been asleep.

Dr Satchidananda Panda, lead scientist from the Salk Institute in La Jolla, California, said: “For a long time, people discounted night-eating syndrome as not real. These results suggest it could actually be a genetic basis for the syndrome. We really never expected that we would be able to decouple the sleep-wake cycle and the eating cycle, especially with a simple mutation. It opens up a whole lot of future questions about how these cycles are regulated.”

When the researchers restricted access to food, providing it only at normal meal times, they found that even with a genetic mutation in PER1, mice maintained a normal weight.

Over a follow-up of ten weeks, these mice – with a PER1 mutation but timed access food – showed no difference to other animals.

Scientists say this suggests that the weight gain caused by PER1 is entirely due to meal mistiming and not metabolic defects.

The team now plans to study exactly how PER1 controls appetite and eating behaviour and whether its molecular actions work through liver, fat cells, brain or other organs.

Aastha Gill