Night owls may have a higher risk of suffering from heart disease and type 2 diabetes than early risers.
In the first ever international review of studies analysing whether being an early riser or a night owl can influence your health, researchers have uncovered a growing body of evidence indicating an increased risk of ill health in people with an evening preference. The problem appears to lie in erratic eating patterns and the consumption of more unhealthy foods that appear to be much more common in night owls.
The human body runs on a 24-hour cycle that is regulated by our internal clock, and which is known as a circadian rhythm, or chronotype. This internal clock regulates various physical functions, such as telling you when to eat, sleep and wake.
An individual’s chronotype leads to people having a natural preference towards waking early or going to bed late.
The Northumbria University researchers found increasing evidence emerging from studies linking conditions such as heart disease and type 2 diabetes to people with the evening chronotype – a natural preference for evenings.
People who go to bed later tend to have unhealthier diets, consuming more alcohol, sugars, caffeinated drinks and fast food than early risers. They consistently report more erratic eating patterns as they miss breakfast and eat later in the day.
Their diets contain fewer vegetables, less rye and grain, and their habits lean towards eating larger but fewer meals. They also report higher consumption levels of caffeinated beverages, sugar and snacks than those with a morning preference, who eat slightly more fruit and vegetables per day.
This potentially explains why night owls have a higher risk of suffering from chronic diseases.
Eating late in the day was also found to be linked to an increased risk of type 2 diabetes because the circadian rhythm influences the way glucose is metabolised in the body.
Glucose levels should naturally decline throughout the day and reach their lowest point at night. However, as night owls often eat shortly before bed, their glucose levels are increased when they are about to sleep. This could negatively affect metabolism as the body is prevented from following its normal biological process.
One study showed that people with an evening preference were 2.5 times more likely to have type 2 diabetes than those with a morning preference.
The review team have called for more studies in the general population that define people’s body clock and how this relates in the long-term to their dietary habits and health.
Are you an early riser or a night owl? If you are a night owl do you find yourself eating before you go to bed? Do you think you could change your behaviour if you wanted to?