Why night owls’ ‘mismatched’ body clock could increase their risk of type 2 diabetes

Night owls have a higher risk of developing type 2 diabetes because their body clock is out of sync, experts have warned.

It is known that those who stay up late are more likely to smoke, eat unhealthily and have a higher body mass index — all factors associated with the condition.

Now researchers suggest the link could also be because their body clock may be mismatched to the rest of society.

They analysed 5000 people who were categorised into three groups, or ‘chronotypes’, based on their sleep timing – late, early and intermediate.

Over the next six years, 225 were diagnosed with type 2 diabetes.

When taking into account age, sex, body fat and lifestyle, the study found people who preferred to stay up late still had a 46 per cent higher risk of type 2 diabetes than those in the intermediate group.

Dr Jeroen van der Velde, who led the study at Leiden University Medical Centre in the Netherlands, said: “A likely explanation is that the circadian rhythm – or body clock – in late chronotypes is out of sync with the work and social schedules followed by society.

“This can lead to circadian misalignment, which we know can lead to metabolic disturbances and ultimately type 2 diabetes.”

The team, who will present their findings at a meeting of the European Association for the Study of Diabetes in Madrid this week, also found that night owls tended to have a higher BMI and larger waists.