Writing in the Archives Of Disease In Childhood, Dr Sigman said such extensive use of televisions and tablets could also lead to attention problems and other psychological difficulties.
The amount of time spent in front of a screen could also adversely affect children's social relationships.
He said many parents use the devices as "electronic babysitters" as a means to occupy their children.
"Screen time appears to have created the three-parent family," he added.
More top news
North Korea has blamed Malaysia for the death of Kim Jong-nam, the half-brother of North Korean leader Kim Jong-un.
Following months of speculation, the former Girls Aloud singer has finally gone public with her pregnancy.
No surprise that David Bowie won at the Brits tonight, the show felt dominated by the stars that have died in the past year.