Smartphone Ownership in Tweens Linked to Higher Obesity Risk: Study

A new study published in the journal of Pediatrics revealed that smartphone owners had a 40% increased risk of obesity when compared to tweens without smartphones.

The age at which young people obtain their first smartphone is constantly declining, and smartphone ownership is becoming almost ubiquitous in early adolescence. This change presents significant issues regarding the effects of early exposure to continuous connectedness on social, mental, and physical health. Long-term wellbeing may be influenced by patterns of screen usage, sleep disturbance, online interactions, and digital habits developed during this developmental window.

To help families, educators, and healthcare professionals encourage better technology usage during these crucial years, research on the relationship between smartphone availability, timing of purchase, and adolescent health outcomes clarifies possible dangers and advantages. Thus, this study examined relationships between early adolescent sadness, obesity, and sleep deprivation with smartphone ownership and acquisition age.

10,588 individuals from the Adolescent Brain Cognitive Development Study were included in the sample. Mixed-effects logistic regression models examined relationships between depression, obesity, and inadequate sleep at age 12 and smartphone ownership and age of first smartphone acquisition, as reported by caregivers.

This study examined relationships between recent smartphone ownership and outcomes in the following year among participants who did not own cellphones at age 12. Models were adjusted for pubertal development, parental supervision, ownership of other gadgets, and demographic and socioeconomic factors.

At age 12, using a smartphone (n = 6739) was linked to an increased risk of depression (odds ratio [OR] 1.31, 95% CI 1.05–1.63), obesity (OR 1.40, 95% CI 1.20–1.63), and sleep deprivation (OR 1.62, 95% CI 1.46–1.79). Obesity and sleep deprivation were linked to younger smartphone purchase ages (OR 1.09, 95% CI 1.02–1.16, and OR 1.08, 95% CI: 1.02–1.12, respectively, for each earlier year of acquisition).

After adjusting for baseline mental health and sleep, among 3486 youth who did not own a smartphone at age 12, those who had purchased one within the previous year (n = 1546) had higher odds of reporting clinical-level psychopathology (OR 1.57, 95% CI 1.12–2.20) and insufficient sleep (OR 1.50, 95% CI 1.26–1.77). Multiple sensitivity studies yielded consistent results.

Overall, owning a smartphone has been linked to early adolescent sadness, obesity, and sleep deprivation. The results offer important and relevant information that caregivers should be aware of when it comes to teenage smartphone use and, ideally, the creation of youth-protective public legislation.

Source:

Barzilay, R., Pimentel, S. D., Tran, K. T., Visoki, E., Pagliaccio, D., & Auerbach, R. P. (2025). Smartphone ownership, age of smartphone acquisition, and health outcomes in early adolescence. Pediatrics, e2025072941. https://doi.org/10.1542/peds.2025-072941