Are you a night owl?
If you’re the type of person who feels wide awake every night and tired every morning, you know how your internal circadian rhythm—also known as your chronotype—can feel out of whack with the rest of society. Being a night owl in a world where the workday starts at 9 a.m. and restaurants stop serving dinner by 9 p.m. can be annoying, to say the least.
But mounting evidence also suggests that there are real health risks associated with sleep-wake cycles that don’t line up with the norm. We spoke with experts, and compiled the latest research, to find out all the ways being a night owl might be bad for your health.
It’s linked to higher blood pressure
In a 2013 study in the journal Chronobiology International, researchers found that “evening types” were 30% more likely than “morning types” to have high blood pressure, even after they controlled for participants’ total amount of sleep and sleep quality.
Dr. Andrew Varga, assistant professor of medicine, pulmonary, critical care and sleep medicine at Icahn School of Medicine and Mount Sinai Health System, says that lifestyle patterns like unhealthy eating or lack of exercise may contribute to night owls’ higher likelihood of hypertension. Stress—both physiological and psychological—may play a big role, as well.
You’re less likely to get your workout in
Self-described night owls spend more time sitting than people who consider themselves early birds, according to a 2014 research abstract in the journal Sleep; they also report having more difficulty finding time to exercise and maintaining a regular exercise schedule.
The people in the study weren’t lazy; they were highly active adults averaging 83 minutes of vigorous activity a week. Still, waking up late or being an evening person made exercise seem much more difficult. Night owls in less active populations would likely find it even harder to get moving, the authors hypothesized.
Most fitness experts agree that the best time of day to exercise is different for everyone, and that optimal timing will depend on a person’s schedule and preferences. But getting up early and working out first thing does have its advantages: A morning workout can give you energy to power you through the rest of the day, and your routine won’t get derailed if something unexpected comes up later on.
Late-night eating may lead to weight gain
“When people go to bed late, they’re up living their lives—and one of the things they’re often doing is eating,” says Varga. “If your bedtime is 3 in the morning, you’re probably eating around 11 p.m. or midnight, and that’s been known to create problems with the way your body handles and metabolizes food.”
Some experts believe that eating after dark disrupts the body’s natural overnight fasting period, which can interfere with its ability to burn fat. Night owls also happen to consume more calories per day than early birds, according to a 2011 study in the journal Obesity–248 more, on average–perhaps because willpower is lower when you’re tired and we tend to crave unhealthier foods late at night.
Night owls have a higher risk of developing diabetes
Several studies have also found that night owls are more likely to have type 2 diabetes than morning people. This may be linked to weight gain, unhealthy behaviors, and getting less sleep overall—but experts also think that just the act of staying up late can affect the body’s metabolism, as well.
“The main role of circadian rhythm is to anticipate what you’re going to be doing at certain points of the day,” says Kristen Knutson, PhD, associate professor of neurology and sleep medicine at Northwestern University Feinberg School of Medicine. “When there’s a mismatch and you’re not doing what your biology expects at a certain time, your body may not handle it as well; it may not process food or glucose as rapidly, for example.”
In one 2015 study, published in the Journal of Clinical Endocrinology & Metabolism, men with evening chronotypes were more likely to have diabetes or sarcopenia (a condition in which the body loses muscle mass), compared to men with morning chronotypes.
Female night owls, compared with their early bird counterparts, tended to have more belly fat and a greater risk of metabolic syndrome—a cluster of conditions (like high blood pressure, high blood sugar, and high cholesterol) that increase a person’s risk for heart disease and diabetes.
And a harder time controlling their diabetes
For those who do go on to develop diabetes, being a night owl can make the condition more difficult to manage. A 2013 study in Diabetes Care found that, for people with type 2 diabetes, having a later bedtime is associated with poorer glycemic control—even after researchers controlled for total sleep duration.
“We know that the amount of sleep you get is important, but this research is also suggesting that when you’re sleeping matters, too,” says Knutson, who co-authored the study. Other research in people with diabetes has also shown a link between evening chronotypes and unhealthy cholesterol levels.
Night owls get less sleep
Speaking of the amount of sleep you get: Night owls also tend to get less overall than those who are early-to-bed, early-to-rise. “If you can’t fall asleep until 2 or 3 in the morning and you have to be at work at 9, you’re not going to be able to get as much good-quality sleep as you really should,” says Varga.
Night owls with weekday jobs tend to make up for some of that lost sleep on the weekends, when they can sleep in. But research suggests that this type of “sleep debt” isn’t that easy to catch up on—and that shifting your sleep schedule on the weekends may come with health risks of its own.
Night owls are bigger risk takers
Staying up late and sleeping in every morning is also associated with a greater tendency for risk-taking, according to a 2014 study in Evolutionary Psychology. While men in the study took more financial risks than women overall, women who were self-described night owls were more daring than those who were early birds.
Female night owls also had higher levels of the stress hormone cortisol, which the study authors suspect is a driving mechanism behind high-stakes behavior. And while taking risks isn’t always a bad thing, it can sometimes lead to dangerous or unhealthy situations, like gambling, substance abuse, or unprotected sex.
They’re also more likely to be single
That same 2014 study also found that night owls, both male and female, were more likely to be single or in short-term romantic relationships. Early birds, meanwhile, were more likely to be married or with long-term partners. Male night owls also reported having had twice as many sexual partners compared to male early birds.
There’s nothing wrong with being single, of course—but research does suggest that, when it comes to health benefits, happily married people often have a leg up. Partners in long-term relationships may motivate each other to stay healthy and visit the doctor, experts say, and the companionship they provide each other is also valuable for mental and physical health.
Early-morning driving may be dangerous
It makes sense that night owls tend to be more tired and less alert in the morning, compared to how they feel during their prime evening hours. But a small 2014 study in the journal Accident Analysis and Prevention suggests there may be real risks to that a.m. sleepiness.
The research, which tested 29 graduate students on driving simulators, found that evening types were less attentive and more prone to errors at 8 in the morning than they were at 8 p.m. Morning types, on the other hand, were more consistent and drove relatively well during both times of the day.
The authors say their findings suggest that employers should tailor individual work schedules around employees’ chronotypes to cut back on people having to drive or perform work-related tasks during “non-optimal” times.
Teenage night owls perform worse in school
It’s not uncommon for teenagers to have trouble falling asleep before 11 p.m. School responsibilities and social distractions are two big reasons, but hormonal changes around puberty can also have a lot to do with teens’ shifted sleep schedule.
Unfortunately, teens aren’t immune to the hazards of staying up late. A 2013 study in the Journal of Adolescent Health found that teens who went to bed later than 11:30 during the school year had lower grade-point averages and were more vulnerable to emotional problems than those who went to bed earlier.
The study underscores the importance of parents enforcing bedtimes and discouraging the use of electronic devices at night, say the authors.
It’s been linked to depression and poor mood
In a 2015 study published in Depression and Anxiety, people with a late chronotype were more likely to have depression and anxiety disorders, compared to people with an early chronotype. Late sleepers were also more likely to report significant mood variation throughout the day, with worse mood occurring in the morning. Other research suggests that the link between chronotype and depression may be especially prevalent in people with diabetes.
That’s not the first time being a night owl had been linked to negative mood and personality traits. In 2008, a study in Personality and Individual Differences found that “morningness” correlated with agreeableness and conscientiousness, while “eveningness” was related to neuroticism in women and adolescents.
Recently, researchers have suggested that night owls may have a harder time regulating their emotions. In a 2017 study in the Journal of Biological Rhythms, scientists found that night owls are more likely to suppress their feelings and less likely to practice cognitive reappraisal (the ability to change the way one thinks about something—to “look on the bright side,” for example) than morning people.
It’s associated with alcohol and tobacco use
A night-owl lifestyle often goes hand-in-hand with other unhealthy behaviors: People who consistently stay up late tend to use more alcohol and tobacco products than those who go to bed early, for example.
Of course, that’s not true for all night owls, and there’s also no evidence that staying up late actually leads to these behaviors. “It’s not clear whether staying up late is a cause or a result of these other lifestyle issues,” says Knutson. “In fact, if you’re staying up late because you can’t fall asleep, these unhealthy behaviors might be a big part of the problem.”
Night owls tend to die sooner than morning people
Even with all of this research, it hasn’t been clear whether the health risks associated with being a night owl are substantial enough to make a measurable difference in people’s lives. But Knutson’s most recent study took a big step toward answering that question.
In a paper published in April in Chronobiology International, Knutson and her colleagues followed about half a million people, ages 30 to 73, for about six and a half years. Over that time, they found that those who identified themselves as “definite evening types” at the start of the study had a 10% higher risk of dying than those who were “definite morning types.”
“People who were definite night owls were also more likely to have pretty much every health problem we looked at,” says Knutson. (Those problems included diabetes, neurological problems, and respiratory disorders, to name a few.) “And now we have evidence to show that staying up late also seems to be connected to early death or mortality, as well.”
It’s not all bad news, though
There are some upsides to being a naturally late sleeper. Night owls tend to have bigger social networks, and some research has found them to be more productive and creative than morning birds. One 2011 study even suggests that night owls have higher levels of cognitive ability, even though they tend to perform worse on academic testing.
Varga also points out that plenty of night owls lead healthy lives, and that more research is needed to determine the real-life consequences of staying up late.
“The true data on this is not very strong, and a lot of it is extrapolated from people in extreme situations, like shift workers,” he says. “It’s still not clear how serious the risks are for people whose patterns may be just a few hours off, so I think some caution is warranted when you’re interpreting these studies.”
What night owls can do
Your chronotype may be ingrained in your DNA, says Knutson, but that doesn’t mean you can’t change it. “About 50% is genetic, but that leaves another 50% where there’s opportunity for shifting your clock,” she says. “But it does require vigilance and consistency with your schedule, which can be a challenge to maintain.”
Night owls can gradually acclimate themselves to an earlier bedtime by turning in a few minutes earlier every night, she says. (Don’t rush it too quickly, or you’ll lie awake for hours.) It’s also important to avoid bright light at night, and to wake up at the same time every day.
Exposing yourself to bright light first thing in the morning can also help reprogram the brain to wake up—and subsequently fall asleep—earlier, says Varga. You can also ask your doctor about taking melatonin, a synthetic version of the brain’s sleep-inducing hormone, key in regulating your internal clock.
But will shifting the body’s natural chronotype actually protect against some of the health risks of being a night owl? “We don’t know the answer to that yet, and that’s where the research needs to go next,” says Knutson.
“For now, I think it’s most important for night owls to recognize that there are health problems associated with their lifestyle,” she adds. “They seem to be more vulnerable to the consequences of a less healthy lifestyle, so they need to be even more vigilant about making smart choices.”