A study following more than 1,800 children from ages 6 months to nearly 8 years old found a small but consistent association between increased television viewing and shorter sleep duration.
Participants in the study, children and their mothers, were enrolled in Project Viva, a long-term investigation of the health effects of several factors during pregnancy and after birth. It analyzed information — reported by mothers when the children were around 6 months old and then annually for the next seven years — regarding how much time each day infants were in a room where a television was on, how much time older children watched television a day, whether children ages 4 to 7 slept in a room where a TV was present, and the average daily amount of sleep.
Each additional hour of television viewing was associated with seven fewer minutes of sleep a night, 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 television reduced average sleep by around 30 minutes a night.
The authors noted that the results supported previous short-term studies finding that both television viewing and sleeping in a room with a television decrease total sleep time, which can have negative effects on mental and physical health.