ANN ARBOR—Preschoolers who spend more time watching television, playing video games or using computers—especially if they’re sneaky at bedtime—get less sleep, say University of Michigan researchers.

Increased media use is linked to a shorter night sleep and a longer daytime nap for preschoolers, according to a new study by Jessica Moorman and Kristen Harrison of the U-M Department of Communication Studies.

Previous research indicates that children aged 2-5 should only use screen media for about one hour a day to ensure their healthy growth and development. This guideline, however, is rarely followed. In the current study, daily screen time for preschoolers was more than double this recommendation.

This isn’t good, because media use can chip away at a restful night’s sleep for young children, threatening their ability to get the 10-13 hours of sleep they need per night, Moorman and Harrison said.

Inadequate sleep among children has been linked to obesity, depression and anxiety, as well as weak school performance and poor social behaviors, such as acting out or displaying aggression toward peers.

The U-M researchers assessed TV, DVD/VCR, video games and computer/internet usage among 278 preschoolers, with average age of 4 years old. Parents and guardians completed an online or paper questionnaire about their child’s bedtime behavior. They reported the hours of nightly sleep, daily naps, and quantity and times of media usage.

In addition to providing demographic information, parents responded to questions about sneaky media use—a new measure representing the frequency children are caught using media when they should be sleeping.

On average, respondents reported their children got close to 11 hours of sleep per day. Most of the children’s media use occurred on weekdays after preschool, in the evening before bedtime and over weekend days.

About 19 percent of the children had televisions in their bedroom and 17 percent had two TVs in their room. More than 23 percent had a DVD/VCR and 9 percent had one video gaming system.

Moorman, a Ph.D. candidate in communication studies and the study’s lead author, said kids caught using media when they should be sleeping, slept less at night, took longer daytime naps and went to bed later on weekdays compared to the never-caught group—all factors that can negatively impact a child’s healthy development.

Not surprisingly, children with televisions in their bedrooms were 127 percent more likely to engage in sneaky media use compared to those without a TV in their room.

Harrison, professor of communication studies and study co-author, said that heaviest media users in the study likely have parents who are also heavy media users. This suggests that families should address these sleep concerns as a unit, not just for the youngest children in the household.

The bottom line: Although the kids are getting more than 10 hours of sleep daily, it’s the timing of that sleep over the day that raises some cause for concern, the researchers said.

“As kids age, they typically grow out of the need for a daily nap, and this process is called ‘sleep consolidation,'” Moorman said.

This can be observed in the differences between the sleep behavior of young infants who sleep at all hours of the day for longer periods of time, and 7-year-olds who can go all day without a nap, getting their 10 hours of sleep in at one shot at night.

“Although these children may be meeting their required hours of sleep during any given 24-hour period, a longer daytime nap suggests a disruption to a child’s process of sleep consolidation,” Moorman said.

The longer naps by the heavy and sneaky media users could be one seemingly innocent yet impactful health-harming behavior in preschool age children, the researchers said.

The findings appear in the current issue of Health Communication.

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