Teens love to sleep. But how long and deep should their sleep be for good health? New studies in collaboration with investigators at the Division of Research find that poor sleep habits in adolescents may increase their risk for obesity and heart trouble down the line.
A study published in Pediatrics tracked 829 adolescents over 7 to 10 days using electronic measuring devices. Sleep time, quality, and physical activity for youth ages 12 to 16 were recorded, along with 5 factors associated with cardiovascular risk: waist circumference, blood pressure, HDL or “good” cholesterol, triglycerides, and insulin resistance.
According to first author Elizabeth Cespedes Feliciano, ScD, a research scientist with the Kaiser Permanente Northern California Division of Research, it was found that very few teens get the kind of sleep they need to protect their future health. Her research shows that those who sleep less tend to have more body fat, elevated blood pressure, and less healthy cholesterol levels.
“Adolescence is a time when you form habits that impact your later risk of cardiovascular disease,” she said. “So, children may be developing cardiovascular risk profiles that they are going to carry forward with them into adulthood.”
A follow-up study reveals even more details. “We saw that the quantity and quality of sleep matter,” Feliciano said. “Preliminary results of our next study suggest that the timing of sleep matters, too.”
Feliciano and her colleagues are looking at teens’ intrinsic preferences for morning or evening wakefulness. “Most teens like to go to bed late — their inner clocks are telling them to go to sleep later and wake later — but their work, school, and social obligations are causing sleep loss because they still have to rise early.”
This misalignment of biological and behavioral sleep timing is known as social jetlag. Like the disruption and disorientation that comes from moving across time zones, it’s a form of circadian misalignment. “It’s that difference between teens’ preferences for when to go to bed, when to eat, when to be active, and socially imposed behaviors. We hypothesize that teens who prefer to be awake in the evening experience more social jetlag and have more body fat,” Feliciano explained.
Fortunately, noted Feliciano, numerous measures can improve teens’ sleep.
1. Sleep at the right time
To combat social jetlag, it’s important that teens develop a consistent sleep schedule that ensures they log enough hours between the sheets.
2. Sleep enough
The American Academy of Pediatrics recommends that teens aged 13 to 18 get 8 to 10 hours of sleep a night. Research shows they’ll have healthier immune systems and better school performance, behavior, and memory.
3. Sleep well
Good-quality sleep is generally characterized by the ability to fall asleep within 30 minutes, sleep soundly through the night, and drift back to sleep within 20 minutes when sleep is disrupted.
4. Set a schedule
Eating late at night can cause insomnia, heartburn, digestive difficulties, and extra trips to the bathroom. Keeping to a regular daily routine for waking, meals, and activities supports teens’ circadian rhythms.
5. Practice good sleep hygiene
“It’s important that adolescents have a quiet, dark, and cool room to sleep in,” said Feliciano, since environmental factors like noise can also influence sleep.
6. Lighten up
Much as a darkened room promotes better sleep, a brightened one helps rouse the body. Exposure to bright light in the morning can make teens feel less drowsy.
7. Eat smart
While limiting caffeine and sugar is important, there are also certain foods that promote better slumber: those rich in the sleep-inducing hormone melatonin (cherries, asparagus, broccoli, tomatoes), high in vitamin B6 (fish, fortified cereals, bananas), high in calcium (milk, yogurt, and cheese), magnesium rich (whole grains and almonds), and high in protein (eggs).
8. Stay active
The American Academy of Pediatrics recommends that kids engage in plenty of interesting and varied activities, including exercise and fresh air, to promote good sleep and general health.
9. Limit screen time
One of the biggest factors disrupting teen sleep, according to Feliciano, is the prevalence of electronic devices in the bedroom at night. And this is not only because their online activity engages them emotionally and mentally. “Screens emit blue light, which has been shown to delay the onset of melatonin secretion,” she said. Turn off TVs, computers, tablets, game stations, and phones an hour before bedtime.
10. Recognize sleep problems
Parents should take note if their teens lack alertness during the day, resist going to bed, have difficulty falling asleep, wake often at night, snore, have sleep apnea, or breathe heavily or loudly while sleeping. A discussion with the child’s doctor may be warranted to treat any problems. Feliciano added, “Parents need to know that sleep is important, just like diet and physical activity, for obesity prevention and the overall health of their kids.”