Study Suggests "Early to bed, early to rise" Can Keep Kids Healthier
A recent study from the University of South Australia has suggested that adolescents who go to sleep and wake up later are at higher risk of becoming obese.
The study, published in the October 1 issue of Sleep, compared the weight and free-time activities of 2,200 young Australians between the ages of 9 and 16. Adolescents who both went to bed and woke up late (termed "late-nighters") were 1.5 times more likely to become obese. The body-mass index (BMI) scores of late-nighters was found to be higher (0.66 vs. 0.45) than those of kids who both went to sleep and got up early (termed "early-risers").
On average, the early-risers went to bed 70 to 90 minutes earlier and got up 60 to 80 minutes earlier than the late-nighters. All of the youths tested got roughly the same amount of sleep.
"Scientists have realized in recent years that children who get less sleep tend to do worse on a variety of health outcomes, including the risk of being overweight and obese. Our study suggests that the timing of sleep is even more important," said Carol Maher, Ph.D., co-author of the paper.
The study also suggested that late-night adolescents, as compared to early-risers, spend nearly 3 times longer in front of a TV or computer. This boils down to an extra 48 minutes a day online, watching TV, or playing video games. Most of this extra screen time was between the hours of 7pm and midnight, when primetime TV and social networking are at a high.
The Australian Department of Health and Aging recommends that youths limit their screen time,including TV and the computer,to two hours or less per day. Of the early-risers, 28 percent met this recommendation, while only 12 percent of late-nighters stayed within this 2-hour boundary.
Late-night adolescents were also discovered to be almost 2 times more likely to be physically inactive during the day than early-risers. On average, 30 minutes of physical activity spent by an early-riser were replaced by 30 minutes of inactivity for the late-nighter, including TV, the computer, or video games.
Adolescents are notorious for going to bed and getting up later than children and adults. "Our findings show that this sleeping pattern is associated with unfavorable activity patterns and health outcomes, and that the adolescents who don't follow this sleep pattern do better," Maher said. This study suggests that it is an unhealthy habit for youths as it can damage their health as they move into adulthood.