TV should be banned for toddlers and strictly rationed for youngsters to protect them from ill health.
Aric Sigman, the associate fellow of the British Psychological Society, describes children spending hours in front of TVs and computers as "the greatest unacknowledged health scandal of our time".
He says it is linked to ills ranging from obesity and heart disease to poor grades and lack of empathy, reports the Daily Mail.
Some children spend as much as seven-and-half hours a day in front of a screen, the equivalent of a full year of 24-hour days by the age of seven.
Sigman believes that the youngest children, whose brains are undergoing massive development, should not watch any TV at all.
From the ages of three to 12, boys and girls should be limited to an hour a day, rising to an hour-and-half for teenagers.
The psychologist will also address an EU parliamentary working group on the issue.
"Most of the damage linked to screen viewing seems to occur beyond exposure of one-and-half hours per day, irrespective of the quality of the content. Yet the average child is exposed to three to five times this amount," says Sigman.