Many studies have shown that people who don't get enough sleep have a higher incidence of overweight. Now, there is new information about the behaviors which cause this.
A new study in the journal Sleep has found that teenagers who sleep fewer than 8 hours/night on weeknights consume more of their daily calories from fat and fewer from carbohydrates when compared to teens who sleeping 8 or more hours/night (remember that teens need, on average, just over 9 hours/sleep a night). The researchers also found that those who slept less than 8 hours/night were more than two times more likely to consume more than 475 calories/day in snacks.
How can these findings be understood, in what context should they be placed, and how can this information be useful to parents trying to get their kids to sleep at a decent hour?
Insufficient sleep has been demonstrated to be linked with disruptions in levels of the hormones ghrelin and leptin, which play a role in mediating the senses of hunger and satiety (feeling full). When this is off, the brain receives an altered picture of the body's need for food, and responds accordingly.
As for the context, it is no secret that overweight and obesity are major health concerns, both for adults and for children. According to data released by the Centers for Disease Control (CDC) last month, an estimated 16.9% of children and adolescents aged 2-19 years are obese, with 18.1%. of children age 12-19 obese.
Teens are notorious for not getting enough sleep. The 2006 Sleep in America poll conducted by the National Sleep Foundation found that 80% of teens got fewer than 9 hours /night of sleep. There are lots of explanations for this, including having "better things to do" (funny how one doesn't hear that about showering, drinking, eating or urinating), social and school pressures, and a lack of synchrony between their internal and external clocks. That chronic sleep deprivation is bad for you in that it can make you sick, do poorly in school, be moodier, have a higher incidence of depressive symptoms, be at higher risk for motor vehicle accidents are not always arguments teens really care about. But when you mention to them that it can also result in their putting on excess body weight, it grabs their attention and concentrates their minds wonderfully.
Using this as a reason to get teens to agree to go to bed (and to sleep) earlier may wind up being a very effective way of improving their lots in all of the other areas as well. As in everything else in medicine (and life), you need to remember who your audience is, or no one will listen to you.
Dennis Rosen, M.D.
Learn how to help your child get a great night’s sleep with my new book:
The Harvard Medical School Guide to Successful Sleep Strategies for Kids: Helping Your Child Sleep Well and Wake Up With a Smile!