If you are a night owl, your natural circadian rhythm is primed to make you feel more alive when the sun goes down. Your eyes shine brighter, your mind feels more alert. The whole world seems to hum.

The bad news is that not being an early bird may be bad for your health, from weight gain to premature death. A 2013 study in the journal Chronobiology International reported that "evening types" were 30 percent more likely than "morning types" to have high blood pressure.

Dr. Andrew Varga, professor of medicine, pulmonary, critical care and sleep medicine at the Icahn School of Medicine at Mount Sinai, said that lifestyle habits such as unhealthy eating or lack of exercise might be part of the problem, Time magazine reported.

Staying up late means that you also might be getting up later. That means you can't go for an early morning run or hit the gym before work. According to a 2014 research abstract in the journal Sleep, night owls have more trouble finding time to exercise and maintaining a regular exercise schedule. They tend to be more sedentary as a result.

As if all of that weren't bad enough, it seems that if you stay up late, you often end up eating then, too. Overeating is a particular problem for people who burn the midnight oil.

"When people go to bed late, they're up living their lives — and one of the things they're often doing is eating," Varga said. "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 health experts warn that eating after dark disrupts the body's natural rhythm of overnight fasting, which undercuts the ability to burn fat. Night owls also tend to consume more calories per day than early birds, according to a 2011 study in the journal Obesity. That may have something to do with the fact that willpower decreases as a long day wears on.

The scariest news of all is that night lovers face a higher risk of premature death. As Forbes noted, a large, observational study of roughly half a million participants from the U.K. Biobank Study found that evening types have a 10 percent higher risk of premature death than morning types.

So that whole early to bed, early to rise thing may be true after all.