The decline in sleep, in turn, can lead to negative effects on both mental and physical health.
Researchers followed more than 1,800 children from ages six months to nearly eight years and found a small but consistent association between increased television viewing and shorter sleep duration.
The presence of a television in the room where a child sleeps also was associated with less sleep, particularly in minority children.
As reported in the journal Pediatrics, the study is the first to examine the connection between television and sleep duration over several years.
Investigators followed children and their mothers enrolled in Project Viva, a long-term investigation of the health effects of several factors during pregnancy and after birth.
This study analyzed information reported by mothers when the children were around six months old and then annually for the next seven years.
Mothers kept track of how much time each day infants were in a room where a television was on, how much time older children watched television daily, whether children ages four to seven slept in a room where a TV was present and their child’s average daily amount of sleep.
Researchers discovered that over the course of the study, each additional hour of television viewing was associated with seven fewer minutes of sleep daily, with the effects appearing to be stronger in boys than in girls.
Racial and ethnic minority children were much more likely to sleep in a room where a television was present, and among those children, the presence of a bedroom TV reduced average sleep around a half-hour per day.
Source: Massachusetts General Hospital