Eating during the day instead of at night boosts mental health, according to new research that suggests eating before bed is bad for the brain.
Shift workers and long-distance travellers may benefit from 'meal time intervention' as both groups are prone to neurological diseases including dementia. A study found symptoms of anxiety and depression rise by 16 and 26 percent respectively after evening meals.
The lifestyles disrupt circadian rhythms - also known as the body clock - sending the brain's grey matter out of kilter and affecting daily behaviours such as sleeping, waking, fasting and eating. The disruption increases the risks of depression and anxiety up to 40 percent.
One-in-five people work irregular hours owing to the 24/7 society. They are needed in hospitals, factories and other essential jobs like transport.
Co-lead author Dr Sarah Chellappa, now at Cologne University, said: "Shift workers - as well as individuals experiencing circadian disruption, including jet lag - may benefit from our meal timing intervention.
"Our findings open the door for a novel sleep/circadian behavioural strategy that might also benefit individuals experiencing mental health disorders. Our study adds to a growing body of evidence finding that strategies that optimise sleep and circadian rhythms may help promote mental health."
Meal timing affected the moods of 19 participants - 12 men and seven women. During simulated night shifts depression and anxiety rose significantly when they also ate late.
In contrast, there were no changes when meals were taken during the day - even though they were working at night.
Dr Chellapa said: "Meal timing is emerging as an important aspect of nutrition that may influence physical health.
"But the causal role of the timing of food intake on mental health remains to be tested. Future studies are required to establish if changes in meal timing can help individuals experiencing depressive and anxiety/anxiety-related disorders."
The volunteers underwent a protocol in dim light for four 28-hour 'days' to invert behavioural cycles by 12 hours - causing circadian misalignment. A Daytime and Nighttime Meal Control Group had meals according to the cycle - resulting in eating both during the night and day which is typical among shift workers.
A Daytime-Only Meal Intervention Group had meals on a 24-hour cycle - eating only during the day. Depression and anxiety levels were measured every hour.
Prof Scheer said: "Future studies in shift workers and clinical populations are required to firmly establish if changes in meal timing can prevent their increased mood vulnerability. Until then, our study brings a new 'player' to the table - the timing of food intake matters for our mood."
In May, scientists at Texas University found eating during the day instead of at nighttime could add years to your life. Experiments found it increased longevity by a third in mice. It added to evidence having a hearty breakfast or lunch - and skipping an evening meal - is healthiest for humans.
Recent years have seen the rise of many popular diets that focus on 'intermittent fasting'' - which includes eating only during a period of six to eight hours per day. The study is in Proceedings of the National Academy of Sciences.
Don't miss the latest news from around Scotland and beyond - sign up to our daily newsletter here .
