Time spent on social media use and BMI z-score: A cross-sectional explanatory pathway analysis of 10798 14-year-old boys and girls.
Pediatric Obesity 2023
Foubister C, Jago R, Sharp SJ, van Sluijs EMF
DOI : 10.1111/ijpo.13017
PubMed ID : 36890676
URL : https://onlinelibrary.wiley.com/doi/10.1111/ijpo.13017
The association between adolescent time spent on social media use and body mass index z-score (BMI z-score) is unclear. Pathways of association and sex differences are also unclear. This study examined the association between time spent on social media use and BMI z-score (primary objective) and potential explanatory pathways (secondary objective) for boys and girls.
Data are from 5332 girls and 5466 boys aged 14 years in the UK Millennium Cohort Study. BMI z-score was regressed on self-reported time spent on social media use (h/day). Potential explanatory pathways explored included dietary intake, sleep duration, depressive symptoms, cyberbullying, body-weight satisfaction, self-esteem, and well-being. Sex-stratified multivariable linear regression and structural equation modelling were used to examine potential associations and explanatory pathways.
Using social media for ≥5 h/day (vs. <1 h/day) was positively associated with BMI z-score for girls (β [95% CI]) (0.15 [0.06, 0.25]) (primary objective, multivariable linear regression). For girls, the direct association was attenuated when sleep duration (0.12 [0.02, 0.22]), depressive symptoms (0.12 [0.02, 0.22]), body-weight satisfaction (0.07 [-0.02, 0.16]), and well-being (0.11 [0.01, 0.20]) were included (secondary objective, structural equation modelling). No associations were observed for boys and potential explanatory pathway variables were not examined.
In girls, high time spent on social media use (≥5 h/day) was positively associated with BMI z-score, and this association was partially explained by sleep duration, depressive symptoms, body-weight satisfaction, and well-being. Associations and attenuations between a self-reported summary variable of time spent on social media use and BMI z-score were small. Further research should examine whether time spent on social media use is related to other adolescent health metrics.
Social media use is widespread and particularly popular for teenagers. Some previous studies have suggested that there may be a relationship between social media use and obesity in teenagers. Most of this previous research has used self-reported height and weight to define obesity, which has substantial limitations. We used data on measured height and weight from 5,332 girls and 5,466 boys aged 14 years in the United Kingdom. We studied the relationship between time spent on social media and weight-for-height (body mass index, BMI). We also explored what may explain this relationship. We therefore looked at the role of food consumption, sleep duration, depressive symptoms, cyberbullying, body weight satisfaction, self-esteem and wellbeing.
We showed that girls who spend five or more hours per day on social media had a somewhat higher BMI than girls who spent less than one hour per day on social media. This relationship was explained in part by sleep duration, depressive symptoms, body weight satisfaction, and wellbeing. There was no relationship for boys.
We conclude that social media use may be related to obesity in girls. However, because the association was small our findings suggest that time spent on social media use may contribute less to BMI z-score than known risk factors (such as dietary intake, and sleep).