Screen time duration and timing: effects on obesity, physical activity, dry eyes, and learning ability in elementary school children

Yui Mineshita,Shota Furuhashi,Mai Kuwahara,Hanako Chijiki,Takuya Nanba,Anzu Suwama,Hyeon-Ki Kim,Shigenobu Shibata,Satoshi Oneda,Takae Shinto

doi:10.1186/s12889-021-10484-7

Abstract

BackgroundAs internet use becomes more widespread, the screen time (ST) of elementary school students increases yearly. It is known that longer durations of ST can affect obesity, physical activity, dry eye disease, and learning ability. However, the effects of ST just before bedtime have not been clarified. Therefore, we examined ST duration and timing effects on elementary school children.MethodsWe conducted a survey of 7419 elementary school students in Tokyo, Japan using a questionnaire on food education. ST duration and timing (just before bedtime) served as the explanatory variables, and the relationship between obesity, physical activity, dry eyes, and learning ability was analyzed using logistic regression analysis. Gender, school year, height, and weight were considered confounding factors. First, we examined whether ST duration and timing were related to each objective variable, using a univariate model to examine all variables. Thereafter, we performed multivariate logistic regression analyses for all variables showing a significant difference in the univariate models.ResultsA significant association was observed between ST duration and obesity, physical activity, and academic performance, indicating that a longer ST duration may lead to obesity, decreased physical activity, and decreased academic performance. ST timing was associated with obesity, dry eyes, and academic performance, and ST immediately before bedtime contributed to obesity, dry eyes, and reduced academic performance. Furthermore, the results of investigating the combined effect of ST duration and timing (immediately before bedtime) on these factors revealed that ST timing has a greater effect on dry eyes, and ST duration has a greater effect on academic performance.ConclusionOur findings indicate that ST in school children is related to obesity, physical activity, dry eyes, and learning ability, and they suggest that not only the duration but also the timing of ST is important.

Highlights

As internet use becomes more widespread, the screen time (ST) of elementary school students increases yearly
The characteristics of the “obese,” “physical activity,” “dry eyes,” and “learning ability” groups are presented in Tables 3, 4, 5 and 6
These results show that the participants with shorter ST durations per day had a better understanding of the material presented in their classes

Summary

Introduction

As internet use becomes more widespread, the screen time (ST) of elementary school students increases yearly. Data from the Cabinet Office of Japan indicate that in 2018, the internet usage rate exceeded 85% for elementary school students, and the average internet usage time increased by approximately 21 min compared to that in the previous year [2]. These data suggest that children are going online at younger ages and that elementary school students’ ST is increasing. In Japan, it was found that approximately 60% of children exceeded the two-hour-per-day maximum of sedentary behavior [5], and approximately half of the Japanese elementary school students did not achieve the recommended physical activity levels [6]. Few studies have examined the relationship between ST and dry eye disease in children

Methods

Results

Discussion

Conclusion