LOS ANGELES — Parents should limit their young children's screen time to no more than two hours per day, according to pediatricians. This recommendation has been in place for many years, but parents and child caregivers don't seem to be catching on. A new study finds that the average preschool-age child is exposed to double the recommended amount.

Screen time consists of television, DVDs, computers and video games. The researchers examined data from nearly 9,000 preschool-aged children who were part of a longitudinal study that began in 2001 and included interviews with parents and child care providers to collect data on each child's daily screen time.

On average, children were exposed to four hours of screen time per day — with 3.6 hours of that time coming from exposures while at home. Children in home-based day care averaged 5.6 hours of screen time at day care. Children in center-based day care watched about 3.2 hours a day while at home and at day care. Even children who did not attend any day care or preschool exceeded recommendations — 4.4. hours a day of screen-time on average. Children enrolled in Head Start, a day care program for economically disadvantaged children, watched an average of 4.2 hours a day, but most of their screen time was at home, not at the Head Start center.

Excessive television, video and computer time is linked to delayed speech and language, aggressive behavior and obesity in children, which is why the American Academy of Pediatrics issued the recommendation to limit exposure to one to two hours per day of quality programming. Most states, however, do not issue regulations regarding screen time as part of licensing of child care centers, the authors noted.

The study was published Thursday in The Journal of Pediatrics.

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