If your teenager suffers from obesity, it’s time to pay very close attention to how much he or she sleeps every night, as this can influence weight loss, or gain.

If they’re not sleeping eight to 10 hours a night, don’t be surprised, because fewer hours of sleep are clearly correlated to teenage obesity, even when TV time is adjusted for. The full report is in the online issue of Pediatrics.

Researchers from the Perelman School of Medicine at the University of Pennsylvania say that fewer hours of sleep in the 14- to 18-year-old study subjects are associated with larger increases in their body mass index (BMI).

The researchers advise that obese teens sleep 10 hours a day, particularly if they’re in the upper range of BMI, to help with weight loss.

The study followed more than a thousand high school teens from ninth grade through their senior year. Every six months, subjects reported their sleep habits, plus BMIs were calculated from regular reports of height and weight.

“Each additional hour of sleep was associated with a reduced BMI for all participants,” says lead study author Jonathan A. Mitchell, PhD, “but the reduction was greater for those with higher BMIs.”

The association was weaker at the lower end of the body mass index distribution. Before you wonder if the snacking that comes with staying up late watching TV is the true culprit of obesity, consider this:

The study adjusted for time in front of TVs and computers, plus physical activity. This suggests that sleep, in and of itself, impacts the propensity to gain or lose weight. More sleep, say the researchers, should be added to the current recommendations of sensible diet and exercise to control teenage obesity.

Unfortunately, explains Mitchell, educating teenagers on sleep benefits goes in one ear and out the other. Furthermore, what if a teenager simply cannot sleep beyond seven hours? Tossing and turning in bed for another few hours isn’t the same as restorative slumber.

Mitchell proposes that high schools delay their daily start. In fact, just a 30 minute delay “results in a 45 minute per day increase in sleep,” says Mitchell, citing previous research.

What can parents of obese teens do in the meantime to help them lose weight? You can’t force someone to sleep. However, as a certified personal trainer, I suggest mandating that your teenagers engage in rigorous exercise daily, to induce longer, restorative sleep.

This doesn’t have to be an unforgiving boot camp approach. It can be as fun as signing your obese teenager up for martial arts (thin frame not required) or fitness classes. A good hour a day of sweating will improve their sleep quality.

Source: sciencedaily.com/releases/2013/04/130408123534.htm