• TYLER OLSON | DREAMSTIME.COM

The American Academy of Pediatrics estimates that about 15 million schoolchildren nationwide don't get enough sleep at night, which can dramatically affect their health, development and academic performance. But many parents, especially those who don't get enough sleep themselves, find it challenging to help their children establish healthy sleep patterns.

This month, Dr. Lewis First, chief of pediatrics at the University of Vermont Children's Hospital, offers tips for helping kids get the sleep they need, so they can wake up feeling refreshed and ready for the day.

KIDS VT: How much sleep do school-age kids need each night?

LEWIS FIRST: All children and teenagers need at least eight and a half to nine and a half hours of sleep per night. That is critical for children who want to do well in school, sports and other extracurricular activities. It also gives them a healthier attitude and helps them emotionally. A good night's sleep can help teenagers who drive reduce their risk of being in a traffic accident. There's also evidence to suggest that sleep-deprived children eat unhealthy snacks with more fats and carbohydrates when they stay up later, which increases their risk of becoming overweight.

KVT: Do older kids have different sleep patterns than younger kids?

LF: As children enter adolescence, their circadian rhythms change, and they don't get sleepy until later at night. The added stress of middle and high school, combined with more homework and other demands, can cut into their sleep time. Melatonin, a chemical the brain releases to make the body tired, gets released later at night in adolescence, which pushes back the time they feel tired and go to bed. As a result, they tend to want to go to sleep later and then wake up later. But if it's a school day, they can't sleep past 6 or 7 a.m., which makes them less alert in their morning classes.

KVT: Do you think public schools should push back their morning start times?

LF: Yes. In 2014, the American Academy of Pediatrics strongly recommended that all schools consider an 8:30 a.m. or later start time, and last month, the U.S. Centers for Disease Control and Prevention reiterated that position. Based on data from the 2011-12 school year, they determined that America's schoolchildren are not getting enough sleep, which is affecting school performance, sports, behavior, diet and more. But, as of 2012, only 15 percent of Vermont public middle and high schools started at 8:30 or later. Vermont's children would be well served in the long run by starting school later and getting a full night's sleep.

KVT: How do parents know if their kids aren't getting enough sleep?

LF: One way is simply to keep track of what time your kids go to bed and when they wake up. Some children may be able to get by on a little less than eight and a half hours of sleep, but parents should watch for warning signs: Do kids struggle to wake up in the morning? Are their teachers reporting that they're having increasing difficulty concentrating as the school year progresses? Are they falling asleep in class? Do they seem more moody, sad or withdrawn? All of these might be signs of sleep deprivation in kids that their parents should talk about with their child's health care professional — and, of course, with their child.

KVT: What's the best way for kids to wind down at bedtime?

LF: First, parents should set regular bedtimes and waking times. They should establish a nightly routine and then decelerate their kids' activities as the evening progresses. Also, turn off electronic devices with screens such as televisions, computers, tablets and smartphones one to two hours before bedtime. Studies show that the blue light emitted by those screens actually inhibits the release of melatonin and doesn't allow the body to relax and fall asleep. Teens are particularly sensitive to that blue light.

Parents should also keep room lights dim toward bedtime and reduce the noise level in the house. Certainly avoid any stimulants, such as caffeinated beverages. Finally, parents should maintain consistent bedtimes and wake-up times even on weekends to help kids establish regular sleep patterns. Remember, the body can catch up on sleep but cannot store sleep for the future.

KVT: What should parents do if their kids are waking up frequently during the night?

LF: First, parents should consider altering their kids' sleep environment as I recommended in the previous question. If kids are waking up and staying up, my suggestion is they should get up and read a book or do something to keep their mind occupied, like little puzzles, until they feel tired again. But don't turn on a TV, and avoid anything that's scary or action-packed.

KVT: What's the best way for kids to wake up?

LF: There shouldn't be any gradual easing into it. Wake them up with an alarm clock or with spirited music, then open the blinds or shades and turn on lights, because the human body is cued to light. That will get them awake and alert and let them start processing things to get their day going. If kids get going earlier in the morning, they'll get tired earlier in the evening and in turn have a better chance of getting the required sleep they need. Finally, all kids need to start the day with a healthy breakfast, which energizes the brain and improves school performance.