In the hustle and bustle of the holidays, it’s easy to forget the point of time off: to relax! Between traveling, meeting up with friends and family, and eating delicious food, the holidays can sometimes be more stressful than the rest of the year and eventually wreak havoc on your health.

For people who decide to forgo sleep in favor of celebrating, beware that the effects may be worse than just grogginess. While you may already know that everyone has an internal clock (called the Circadian rhythm) that tells us when to sleep and wake, you may not realize that this clock can influence several other health conditions.

A recent study found that teenagers who did not get enough sleep had higher insulin resistance, which can lead to diabetes. This follows a 2006 study showing that people who sleep less have higher rates of obesity and diabetes. In contrast to the common-sense conclusion that sleeping longer makes you lazier or more overweight, the study actually found that people who slept less were hungrier and produced more insulin, leading to insulin resistance.

But what if you normally get enough sleep and you just lose a few hours to the holiday? Unfortunately, even the few extra hours that you are awake each day can be enough to trigger your appetite and make you overeat, leading to weight gain. Another study found that even one night of lost sleep stimulated the part of the brain related to your desire to eat, making you hungrier.

And science indicates that the contrary hold true as well. If you’re trying to lose weight, getting enough sleep can help you eat less and move more, the two most vital components to any diet plan. Getting enough sleep can also help you make better dietary decisions and choose healthier foods.

If you have trouble getting to sleep, exercise can help you regulate your own internal clock. A recent study in mice showed that mice whose internal clock was off kilter could regulate their clocks by exercising. Exercising in the afternoon rather than the morning seemed to be especially beneficial. And late night exercise (after 11 pm) had the opposite effect, disrupting their internal clocks.

Other benefits of sleep include reduced pain sensitivity, according to a study from this past month. And a Swedish study found that the idea of “beauty sleep” isn’t just a myth; participants that slept longer appeared healthier and more attractive.

Learn about other ways to stay healthy over the holiday season!