Children's Screen-media Use

Screen-media use has become part of our life. From TV, videos, video games, computer, internet, to smartphone and tablet computer, children can access these technology products easily through adults. Many consider screen-media learning an inevitable trend for children. However, have we thought about the impact on children?

The effects of screen time on children’s health

Studies have shown that screen time spent is positively correlated with obesity in children (Note 1,Note 2). Children’s amount of physical activity will decrease and they will tend to eat snacks while sitting down to watch TV or videos. Children are more likely to consume more ‘junk snacks’ as snacks advertisements appear far more frequently during children’s programme on TV. Besides taking up time in physical activities, screen time itself is a risk factor for cardiovascular disease. (Note 3,Note 4) Studies show that the longer the screen time spent on TV or video games, the higher children’s blood pressure, non-HDL cholesterol and insulin resistance (HOMA-IR). These factors are also associated with cardiovascular disease in adulthood.

Screen time is also shown to be associated with sleep quality (Note 4,Note 5), especially night time sleep. Screen viewing tends to disrupt children’s sleep routine. They will have shorter sleep hours, and may even be distressed by the content of TV progamme, leading them to have sleep anxiety or waking up at night. Some parents may allow children to have screen viewing (including TV, tablet computer and smartphone) at mealtime. As a result, the screen distracts the child from the food. They will only swallow food passively without enjoying it and do not learn feeding themselves independently. It will be difficult for them to build up a healthy eating habit.

There are numerous children’s TV programmes, videos and computer software having educational claims of promoting children’s language and learning abilities.  Whether they are educational depends on their content as well as how they are used. There is growing evidence on the relationship between screen time and children’s language. In summary, for children below aged two, there is no increase in their vocabulary when they watched these educational materials on their own. On the contrary, the longer the total viewing time, the higher the risk on language delay (Note 6). For the materials to be helpful for language acquisition, children under three must be accompanied by an adult who will guide them during viewing. Parent-child interacting and talking alone is even more facilitative for children to learn language when compared to screen viewing with parent guidance (Note 7,Note 8).
We also need to avoid children viewing screen for a long time or at a near distance. Tired eyes will get dry easily and there will be accommodation problems. It may have negative effect on children’s vision.

The effects of screen time on children’s behavior

Children learn by imitation. Some children increase in aggressive behaviour after watching aggression on TV, videos or video games (Note 9). When children see adults using a lot of screen time, they will do the same. The longer the screen time, the less social contacts there will be. In the long run, children’s empathy and social skills could be compromised (Note 4).

Preliminary findings suggest that screen time in early childhood can link to attention deficit in adolescence (Note 10) although the actual relationship is not known. We should note the phenomenon of multi-tasking is already occurring among children (Note 11). For example, they may do homework, watch TV and play with smartphone at the same time. Continuous attention focus on different tasks and task switching will overload the brain, leading to difficulties in attention control as well as lack of in-depth analytical thinking and decision making.

Effective strategies for reducing screen time

A systematic review on interventions on screen time of children from 1998 to 2001 identified three most effective strategies used (Note 12). They were: using electronic TV monitoring devices to monitor the viewing time and content of TV programme or internet; contingent feedback systems to trade off TV time with time in physical activity; and clinic-based counseling in media education to parents in Women, Infants and Children(WIC) programmes. A crucial factor for the effectiveness of the strategies is the active participation of the parents.  

The sites of these interventions covered schools, communities, WIC clinics and home visits. The review sheds light on the role of educators, community workers and health professionals in media education. The professionals should take time to explore the parents’ view on screen time and how much screen time their children use. They can educate the parents on the benefits and damages of screen time. As educators, community workers and health professionals, we must also reconsider if TV and video shows for children in the waiting area or at break times could be replaced by other activities.


The American Academy of Pediatrics recommends no more than two hours per day of screen time for two years old and above (Note 13), and children under two should avoid contact with any screen-media (Note 14). Very often, young children, especially those under two, have ‘second-hand screen time’ – in particular ‘second-hand TV’ – when adults are viewing screen-media around them. They take in far more information from the screen than we could imagine. A one-year old toddler is able to learn emotional responses from TV (Note 15). As the immature brain of infants and toddlers is vulnerable to external stimuli, we need to be alert to providing them ‘second-hand screen time’ or using screen-media as babysitter (Note 4,Note 14). Even background TV can affect the amount and the quality of parent-child interaction (Note 16).

More information on the positive and negative impacts of screen-media on adolescence can be found in the linked paper and the Non-Communicable Diseases Watch published in July, 2013 by Department of Health.


  • As role models for children, parents need to cut down screen time./li>
  • Don’t place any screen-media in the bedroom.
  • Parents should monitor children’s screen-media use. Don’t often leave screen-media on.
  • Set up limits and consequences on children’s screen time use and consistently follow through.
  • Be careful in choosing the content of screen-media.
  • Adults should accompany children and talk about the content of the screen-media. Give children intermittent short breaks during screen time.
  • If possible, spend as much quality time with children, e.g. talking, reading, play and physical activities to replace screen time in order to promote the cognitive, physical and emotional development of children.