This Could Explain Disease Risk for Night Owls

Study finds people who go to sleep, wake later are less active, burn more carbs than early birds
By Arden Dier,  Newser Staff
Posted Sep 20, 2022 9:40 AM CDT
This Could Explain Disease Risk for Night Owls
Staying up late may come with hidden risks.   (Getty Images/BrianAJackson)

There are hidden health risks to being a night owl, including a higher risk of heart disease, which might come down to metabolism, according to new research comparing the sleep patterns of night owls and early birds. There are clear differences between the two: Night owls generally feel most energized in the afternoons or evenings but sluggish in the mornings. That's because for them, the release of melatonin, which makes you sleepy, occurs later at night and tapers off later in the morning than it does for early birds—which is why the latter group's peak energy often comes in the morning. But as in other research, this study of 51 obese middle-aged adults who were monitored for a week found early birds tended to be more active overall, per the Guardian.

Night owls were more sedentary, had lower aerobic fitness levels, and were more likely to be insulin-resistant, meaning more insulin is needed for muscles to take up glucose for energy. "Insulin tells the muscles to be a sponge and absorb the glucose in the blood," study co-author Steven Malin of Rutgers University tells CNN. "But if you're not exercising, engaging those muscles, it's like if that sponge was to sit for a couple days and get rock hard." While the bodies of night owls favored carbohydrates as an energy source, early birds burned more fat, which will "help the muscle pick up the glucose in a more enduring fashion," says Malin, whose research is published in Experimental Physiology. This in turn "can promote endurance and more physical and mental activity throughout the day," per CNN.

These metabolic differences "could help medical professionals consider another behavioral factor contributing to disease risk," Malin says, per the Guardian, noting "night owls are reported to have a higher risk of obesity, Type 2 diabetes, and cardiovascular disease" compared with early birds. However, he says it's too soon to know whether the metabolic differences result from one's sleep chronotype (which CNN notes is believed to be inherited) or rather a misalignment with one's circadian rhythm. Night owls might simply be suffering as a result of needing to wake early—say, for work or child care—because that's the way society has been set up. (More night owl stories.)

Get the news faster.
Tap to install our app.
Install the Newser News app
in two easy steps:
1. Tap in your navigation bar.
2. Tap to Add to Home Screen.