Chldren may be tempted to stay up late watching television
Not only does access to a television provide too much temptation for many children who should be getting at least eight hours sleep, the content of programmes can leave them over-excited, disturbed or frightened.
Researchers found that the problem was worse if children had a television in their bedroom.
The study was published in the journal of the American Academy of Pediatrics.
It is the second critical report on television from the journal in a month. In August, the Academy published a policy statement suggesting children younger than age two should not watch television at all.
That statement said research on early brain development shows babies and toddlers have a critical need for direct interaction with parents and other adults that TV may block.
The new study, from Hasbro Children's Hospital and Brown University in Rhode Island, said doctors "should be aware of the potential negative impact of television viewing at bedtime" and recommended parents "be questioned about their children's television viewing habits as part of general screening for sleep disorders."
Researchers surveyed the parents of 495 children aged five to10 to assess sleep behaviour and TV viewing habits.
They found increased daily TV viewing and increased viewing at bedtime were associated with sleep disturbance, especially when children had a set in their bedroom.
One in four parents surveyed said their children had bedroom TV sets.
Sleep characteristics most often affected included bedtime resistance, sleep onset delay, anxiety and shortened sleep duration, the report said.
The researchers suggested that children might be over-stimulated, disturbed or frightened by the content of programmes particularly those containing violence.
However, they also suggest children might not sleep well after watching television because they were not taking exercise.
"Television viewing may simply serve to displace sleep time," the article said.
Professor Neil Douglas, director of the Scottish National Sleep Centre, said: "It seems eminently sensible that children should be encouraged not to spend large periods of their evening watching television.
"There is reasonable evidence that ability to concentrate and work well at school does relate to how well children have slept at night. Regular disturbed nights does affect school performance and decreases measurable IQ."