What Your Weird Sleep Schedule Is Doing to Your Body

Your late nights could be causing serious harm—regardless of how much you drink.

Woman with brown hair asleep
(Image credit: Getty)

It doesn't matter whether your typical weekend involves ripping tequila shots or watching movies: If you stay up later than usual, your social life could be messing with your health.

In a new study (opens in new tab), researchers assessed the health markers and sleep habits of 815 New Zealanders involved in the Dunedin Longitudinal Study. To assess the difference in their sleep schedules on weekends versus weekdays, researchers compared sleep midpoints (i.e., 4 a.m. if you turn in at midnight and wake up at 8 a.m.) on different days of the week.  

People whose sleep schedules varied by more than two hours were significantly more likely to be obese and have inflammation, high blood pressure, high blood sugar, and other risk factors linked to coronary artery disease, stroke, and type-2 diabetes.

While researchers didn't set out to determine why, they do know that sleep affects your circadian rhythm, which plays a role in fat metabolism and can aggravate disease risk factors. Another one of their theories: Shake up your sleep schedule, and you could fall prey to other unhealthy habits (i.e., binging on late-night snacks or sleeping through a morning workout). 

Previous studies (opens in new tab) have shown that shift workers who regularly change up their sleep schedules tend to have poor health and be overweight. And while this new data uncovers an association, not causation, the findings suggest that anyone who sometimes stays up later than usual (i.e., everyone) could be endangering their health too. 

Still, no one wants to turn in early on a Saturday night or set a Monday-style alarm Sunday morning. Your next best bet is to eat at regular times (opens in new tab) and get some sunlight when you start your weekend mornings on the later side. This should help readjust your body's biological clock.

You should also check out: 

7 Myths About Sleep (opens in new tab)

10 Ways to Wake Up Prettier Than You Went to Sleep (opens in new tab)

7 Bedtime Habits That Are Ruining Your Sleep (opens in new tab)

Elizabeth Narins
Elizabeth Narins

Elizabeth Narins is a Brooklyn, NY-based writer and a former senior editor at Cosmopolitan.com, where she wrote about fitness, health, and more. Follow her at @ejnarins.