For growing children, adequate sleep is every bit as important as nutritious food and daily exercise. Yet, ever since Edison flipped on the first electric light, experts have been worrying about whether any of us are getting enough sleep. Now researchers are warning that online amusements, especially social media, are sabotaging sleep. Not long ago, the New York Times ran an anxious story about adolescents who “vamp”—staying up all night and using cellphones to surf, text, tweet, play games and binge watch their favorite shows. Apparently, some teens even text in their sleep, sending messages they don’t remember the next day.

The best way to counteract these trends is to teach good sleep habits when kids are young and parents are firmly in control. Throughout elementary school, it’s a good idea to establish a clear bedtime by counting backward 10-11 hours from when a child needs to be up in the morning. To help kids fall asleep, guide them toward a predictable, self-soothing routine: a warm bath, getting things organized for the day ahead, low lights, soft music, a bit of reading, a snuggle with a stuffed animal. The specific ingredients may vary depending on child’s age and temperament, but experts point out that learning to do something consistent in preparation for sleep has lifelong benefits.

In middle school, children grow rapidly, so they still need more sleep—and less social media—than they think they do. Sleep experts recommend that bedrooms be tech-free zones—no cellphones, video games or televisions. Period. Get an old-fashioned alarm clock, and insist that all devices observe a curfew in a room you can supervise. Make it a goal for everyone in the family to get an hour of tech-free time before bed.

By high school, most kids will challenge these rules, so parents need new strategies. The most effective is to talk to teens about how plenty of sleep at night makes them happier during the day. The goal is to help kids develop a genuine appreciation for the benefits of sleep so they will make healthy decisions even when you aren’t around. Here are some points worth making:

How Much is Enough. Rather than arguing about how much sleep he or she needs, make your teen responsible for behaviors associated with being well-rested. Can your child get up at the right time in the morning and do what needs to be done without nagging from you? Can he or she stay awake and pay attention at school? Is your teen able to get through most days without being hostile, grouchy or irritable—all common side effects of fatigue? Explain to your child that when the answer to all these questions is yes, you will back off about bedtime. If you see slippage in schedules, grades or moods, you’ll need to reassert control.

How Much Sleep Do Kids Need?

Information from the National Sleep Foundation. For more info, visit SleepFoundation.org.

The Risks of Too Little. Teens need to know about research showing that too little sleep has consequences for physical and mental health. In addition to the negative effects on mood and attention, sleep deprivation is also associated with higher blood pressure and an increase in stress hormones. Teens may also be interested to know that some researchers have connected too little sleep to increased feelings of hunger which may lead to weight gain.

Online Seductions. Teen aren’t going to want to hear this, but sleep experts are convinced that being online before bedtime makes it harder to fall asleep. For one thing, light is a stimulant that interferes with the sleep cycle. In addition, many online pastimes—competitive games, social media “drama,” provocative programs—activate emotions that thwart sleep. If your teen resists the idea of disconnecting at bedtime, talk about what’s going on. Some teens whose lives are heavily scheduled feel that their only unstructured time occurs after “lights out.” Others experience FOMO (fear of missing out) whenever they are offline. Understanding why your teen wants a phone under the pillow may help you work together to establish better boundaries and balance.

Becoming Self Aware. Teens are more likely to make sleep a priority when they are aware of their own patterns, so encourage your child to keep a sleep diary. What time did he or she get into bed? How long did it take to fall asleep? What was happening immediately before bedtime? Did he or she wake up spontaneously (a sign that sleep was adequate)? When was your child tired during the day? Did he or she take a nap in the afternoon? How long? Did he or she wake up refreshed or groggy? Doing this for a week or two may help your teen make the connection between better sleep and better performance during the day.

Finally, remember that children who lead full and complicated lives may need help with the kind of off-line relaxation that leads to restorative sleep. Depending on your family’s values, you may want to encourage your child to pray, count blessings, meditate, keep a gratitude journal, focus on deep breathing or write down problems so they can be set aside. All of these are time-tested strategies for stepping away from the pressures of a 24/7 world and finding peace at the end of the day.

Carolyn Jabs, M.A., raised three computer savvy kids including one with special needs. She has been writing the column “Growing Up Online” for more than a decade and is working on a book about constructive responses to conflict. Visit Growing-Up-Online.com to read other columns.