Monica Aurilio knows she’s a rare bird. For 27 years now, she’s been a nurse on the night shift at Brigham and Women’s Hospital by choice.”Through school, I waitressed and worked nights and did best until two or three in the morning,” Aurillo said. “I think that was always my thing.”So when she started her career at Brigham, Aurillo decided to take the 7 p.m. to 7 a.m. schedule that few others wanted.”I don’t like to get up early in the morning,” she said.For Aurillo, her nightside schedule has been a natural fit.Researchers agree that understanding how our own body clock — or chronotype — works is important.Studies show people typically fall into one of three groups.True night owls like Aurillo stay up late and sleep in, but that only applies to 10% of the population.More common are early birds, which are about 30%. They wake up before the sun and generally go to bed early, too.The remaining 60% falls somewhere in the middle. Researchers refer to that group as “intermediate.”What’s still unclear is the reason why.”The geographical location and gender have an influence on our chronotype, but genetics also shape a significant portion of it,” said Sina Kianersi, an expert in chronotypes at Brigham.His research has shown whether we stay up late or go to bed early affects more than just our sleep. It also appears to influence our lifestyle choices, particularly for night owls.”We found this consistent pattern of smoking, having a poor diet, having a poor BMI or weight,” Kianersi said. “Overall, they were 54% more likely to have an overall unhealthy lifestyle when we compared them to early birds.”There are theories, of course.The research suggests most night owls are “out of sync” with the rest of the world.They may work during the day, but their chronotype keeps them up at night — literally.Less sleep, less activity, and more eating for those extra hours may explain their higher risk of developing Type 2 diabetes.”The good news here is that night owls, by maintaining a healthy lifestyle, can decrease their risk substantially,” Kianersi said.That’s especially true for people like Aurillo, who can embrace their chronotype and build a life around it.”When I’m passing through patients’ rooms at 5 a.m., I’m like, ‘Oh everybody, look at the sunrise!” she said. “So I see the sunrise. It’s just on the different end of it.”Interested in learning more about your chronotype? Click here to take a free online test.