JOIN USNight owls - people who stay up late and have trouble coming out of bed in the morning - have a higher risk of dying sooner than larks, those who go to bed early and rise with the sun, a study has found.
The research on nearly half a million participants in the UK Biobank Study found that owls have a 10 per cent higher risk of dying than larks.
In the study published in the journal Chronobiology International, 50,000 people were more likely to die in the six and a half year period sampled.
"This is a public health issue that can no longer be ignored," said Malcolm von Schantz, a professor at the University of Surrey in the UK.
The scientists adjusted for the expected health problems in owls and still found the 10 per cent higher risk of death.
They found that owls had higher rates of diabetes, psychological disorders and neurological disorders.
"We should discuss allowing evening types to start and finish work later, where practical. And we need more research about how we can help evening types cope with the higher effort of keeping their body clock in synchrony with sun time," von Schantz said.
According to Kristen Knutson, associate professor at Northwestern University in the US, people who are up late may have an internal biological clock that does not match their external environment.
"It could be psychological stress, eating at the wrong time for their body, not exercising enough, not sleeping enough, being awake at night by yourself, maybe drug or alcohol use. There are a whole variety of unhealthy behaviours related to being up late in the dark by yourself," said Knutson.
Genetics and environment play approximately equal roles in whether we are a morning or a night type, or somewhere in between.
"You are not doomed. Part of it you do not have any control over and part of it you might," Knutson said.
One way to shift your behaviour is to make sure you are exposed to light early in the morning but not at night, Knutson said.
The researchers suggests that people should try to keep a regular bedtime and not let themselves drift to later bedtimes.
"Be regimented about adopting healthy lifestyle behaviours and recognise the timing of when you sleep matters. Do things earlier and be less of an evening person as much as you can," they said.