A fairly comprehensive Review of Reviews on the correlated impacts of screen time for children and young people (CNY) ages <18. This review used a standard systematic review rating system (AMSTAR) to segment the reviews looked at in this review. 13 reviews were identified (1 high quality, 9 medium and 3 low quality).
The great majority of findings related to television screentime. Data on other forms of screentime were very sparse.
We noted dose-response findings where relevant. We made no attempt to quantitatively summarise findings across reviews as quantitative summaries should be undertaken at individual study level rather than at review level.
Conclusions There is evidence that higher levels of screentime is associated with a variety of health harms for CYP, with evidence strongest for adiposity, unhealthy diet, depressive symptoms and quality of life. Evidence to guide policy on safe CYP screentime exposure is limited.
We found moderately strong evidence for associations between screentime and greater obesity/adiposity and higher depressive symptoms; moderate evidence for an association between screentime and higher energy intake, less healthy diet quality and poorer quality of life. There was weak evidence for associations of screentime with behaviour problems, anxiety, hyperactivity and inattention, poorer self-esteem, poorer well-being and poorer psychosocial health, metabolic syndrome, poorer cardiorespiratory fitness, poorer cognitive development and lower educational attainments and poor sleep outcomes. There was no or insufficient evidence for an association of screentime with eating disorders or suicidal ideation, individual cardiovascular risk factors, asthma prevalence or pain. Evidence for threshold effects was weak. We found weak evidence that small amounts of daily screen use is not harmful and may have some benefits.
Some of the evidence pointed to junk food marketing as a primary culprit for poor health outcomes, seeing impacts associated more with TV than video games as an example.
In a medium-quality review of experimental studies, Marsh et al reported that there was strong evidence that i) screentime in the absence of food advertising was associated with increased dietary intake compared with non-screen behaviour; ii) television screentime increases intake of very palatable energy-dense foods and iii) there was weak evidence for video game screentime similarly increased dietary intake. They concluded there was moderate evidence that stimulatory effects of TV on intake were stronger in overweight or obese children than those of normal weight, suggesting the former are more susceptible to environmental cues.
This review also notes weak evidence of negative impacts of vscreentime and cognitive development. Though there are strong associations for harm for infants.
LeBlanc et al reported that there was low-quality evidence that television screentime had a negative impact on cognitive development in young children. Evidence was stronger among infants, where LeBlanc et al concluded that there was moderate-quality evidence that television screentime elicited no benefits and was harmful to cognitive development. Tremblay et al reported there was poor evidence that greater television screentime was associated with poorer educational attainments. Carson et al also noted weak evidence that screentime or television screentime were associated with poorer attainments.
