Night Owls Might Be at Higher Risk for Diabetes and Heart Disease

If you tend to stay up late, you might be at a higher risk of chronic diseases such as type 2 diabetes and heart disease, according to a new study.

The research, which was recently published in the journal Experimental Physiology, looked at how being an “early bird” or “night owl” might affect a person’s health.

The findings showed that night owls were more sedentary and likely to be insulin-resistant. That means their muscles need more insulin to get the energy they require.

Compared to early birds, night owls also had a reduced ability to burn fat for energy. That could lead to a buildup of fats in the body and an increased risk for type 2 diabetes and heart disease. 

Early birds were more sensitive to insulin and had higher fitness levels than night owls.

“The differences in fat metabolism between ‘early birds’ and ‘night owls’ show that our body’s circadian rhythm could affect how our bodies use insulin,” Steven Malin, PhD, FACSM, a senior author of the study and an associate professor of metabolism and endocrinology at Rutgers University, told Verywell.

Malin said that chronotypes—one’s preference to sleep or wake at a certain time—appear to affect metabolism and hormone action. Therefore, the researchers suggest that chronotypes could be used as a factor to predict a person’s risk of disease.

The Health Risks of Being a Night Owl

The researchers included 51 adults in the study. Based on how they answered questions about their sleep habits, the participants were put into two groups by chronotype—that is, whether they were night owls or early birds.

According to Malin, night owls generally went to bed at either 1 a.m. and woke up closer to 9 a.m., while early birds went to bed at 11 p.m. and woke up at around 6:30 a.m. 

All of the participants exercised less than 60 minutes a week (considered sedentary), were non-smokers, and did not have cardiovascular disease, cancer, or metabolic diseases. 

The participants also wore a device to measure changes in force and movement (accelerometers) during the day for seven days. This gave the researchers information about when the participants were the most active.

The researchers compared the participants’ physical data to their questionnaires to see if their sleep chronotypes might be influencing their activity patterns during the day.

According to Malin, the researchers noted that night owls had lower fitness levels and were more sedentary throughout the day than early birds—particularly in the morning and in the middle of the day.

Based on that observation, Malin said that “activity patterns and fitness are important from the current work and are related to fat metabolism and insulin sensitivity.”

What Makes Being a Night Owl Risky?

According to Malin, it’s not entirely clear why night owls might be at higher risk for chronic health conditions, but insulin resistance could be a key factor.

Malin said that insulin is vital because it “promotes glucose uptake into tissues, like skeletal muscle.”

Having a poor diet and not getting enough physical activity are common reasons why someone develops insulin resistance. More recently, a lack of sleep has also been identified as a key behavioral factor that likely contributes to insulin resistance.

“Targeting a healthy diet, activity, and sleep pattern is thought to prevent the transition from health to insulin resistance and type 2 diabetes,” said Malin.

Richard Wright, MD, a cardiologist at Providence Saint John’s Health Center, told Verywell that when you inject someone with insulin, their blood sugar normally goes down. However, if they are not as sensitive to insulin, their levels won’t fall as much.

“We know that insulin resistance correlates with body weight,” said Wright. “The more sensitive you are to insulin correlates with less body fat, more muscle mass, fitness, longevity, and the presence or absence of type 2 diabetes.”

Wright added that there are likely other reasons why night owls might be at a higher risk for type 2 diabetes and other health conditions—including sleep deprivation, interrupted sleep, and unhealthy behaviors like a diet that’s lacking nutrition and not getting enough physical activity.

According to Wright, research has shown that interrupted sleep, bad quality sleep, or not getting enough good sleep “correlate with poor health and longevity.”

The takeaway? “People who sleep well typically live longer,” Wright said.

While the recent study seems to support the idea that people who choose to get up early are better off metabolically, Wright cautioned that more research is needed to prove that getting up early is the reason that they’re better off.

Should I Try to Become an Early Bird?

While the study showed a link between sleep chronotype and chronic diseases, Wright said that it does not prove the relationship is a causal one.

Still, if the research has you thinking about how your sleep pattern might be affecting your health, it could be worth experimenting with your routine.

Malin said that if you want to make a change, do it gradually. For example, start with small steps like going to bed 15 or 20 minutes sooner or waking up a few minutes earlier.

If there are downsides to being a night owl, are there also risks of being an early bird? Wright said he does not see any information in the data that getting up early is harmful.

Habits to Lower Your Chronic Disease Risk

Whether you’re an early bird or a night owl, there are plenty of other things you can do in your life to lower your risk for chronic diseases, such as:

• Get exercise daily, whether it’s in the morning or during the day. 
• Break up any sedentary time in your day. Try stretching or doing other types of movement for about 2 minutes every hour or taking short walks after meals.
• Incorporate different movements into your day including body squats, push-ups, and other weight lifting exercises.
• Avoid stressful or vigorous activity late in the evening to help prepare your body for sleep. 
• Try to get into a routine for healthy sleep, like waking up at the same time every day. 
• Avoid high sugar foods, caffeine, or alcohol later in the day, especially at night close to when you want to go to bed.
• Put away technology like phones, tablets, and televisions with blue light at night, since these can trick your circadian clock into making you want to stay awake.