As students head back to school, they might be tempted to stay up late during the weekend, but one sleep doctor said doing so could hurt the body.
"Sleep is a natural repeated function like breathing or the heartbeat," said Dr. Alexander Villareal, a sleep medicine board-certified physician for the Geisinger Health System. "The body tells you to sleep."
That is necessary to let the body recharge, but changing a sleeping schedule can cause the same sleepiness as jet lag from traveling overseas.
Most people need seven to eight hours of sleep, but someone who tends to stay up late on the weekends could suffer from chronic sleep deprivation. Some people sleep less during the week, such as six hours, and try to make up for that sleep on the weekend.
Lack of sleep then could make the person feel hungrier.
That deprivation can cause changes in the hormone system because people might experience lower levels of the hormone leptin, which makes people feel full after they eat.
There also could be higher levels of the hormone ghrelin, which increases appetite and cravings for carbs, Villareal said.
Sometimes people say, "I'm tired. I need to have some sugars to help me stay awake," Villareal said.
Spending more time awake on the weekends means more time for people to make unhealthy food choices at a time when metabolism is slowed down.
"People who don't get enough sleep - less than eight hours - tend to gain more weight than those who do," Villareal said. "It happens over a long period of time - months or years. People who get less sleep, someone who gets seven hours, is more likely to be obese than someone who sleeps eight hours."
That chance increases with the decrease in hours slept.
People who have an active social life may find it difficult to get the sleep necessary to keep the body healthy.
"It's balancing the social needs with biological needs," Villareal said. "Make a priority of attaining enough sleep. Get seven to eight hours of sleep so (you) can function better."
If someone is too busy to get a full night's rest, taking a short nap may help, he said. The ideal nap would be in the early afternoon and no longer than half an hour.
Taking a nap for more than 30 minutes in the daytime could take away from the sleepiness at night.
"It makes it more difficult to sleep at night (because people) get in deeper stages of sleep," Villareal said.
Yet for the people who have a hard time sleeping because they have insomnia, that rule changes since it is not that they willingly are avoiding sleep.
There also are people who work different shifts, such as nurses and factory workers, who need to adapt their sleeping schedules.
The best recommendation he can give for someone who works varied hours is to try to consistently get up at the same time - even if that means not sleeping in on days off.