Tween smartphones tied to eating disorder symptoms in teens

Clinical takeaway: Ask about phone ownership when assessing disordered-eating risk in young adolescents, and treat the when-to-get-a-phone question parents raise as a health conversation. 

Nearly all US teens can get their hands on a smartphone. With the age for a first personal smartphone creeping younger every year, parents routinely bring the timing question to clinicians but usually as a matter of distraction and screen time. Disordered eating rarely figures into that conversation, even though the symptoms take root in exactly the years a first phone tends to arrive. 

A phone of one's own at 12 years old has been associated with depression, obesity, and insufficient sleep. More hours of screen and social media use track with more eating disorder symptoms two years on. Now, a large US cohort study helps give a clearer answer on the phone-timing decision for kids. 

Adolescents who owned a smartphone at age 12 carried a 49% higher risk of reporting at least one eating disorder symptom by age 14 than nonowners. Risk of tying self-worth to weight roughly doubled, binge-eating symptoms ran 67% higher, and inappropriate compensatory behaviors to prevent weight gain ran 50% higher. Worry about weight gain was the sole exception, showing no association with ownership at either age. 

Owners already looked different at 12, though not on every measure: binge-eating symptoms ran 61% more prevalent than among nonowners, self-worth tied to weight more than twice as prevalent, and any symptom 36% more prevalent, while compensatory behaviors did not differ significantly. When analyses split by sex, the cross-sectional association between ownership and worry about weight gain appeared in females but not males, a suggestive pattern the overall models did not bear out. By 14, nearly one in four owners reported at least one symptom, and compensatory behaviors had become the most common at about one in five. 

The findings come from 8,957 adolescents in the Adolescent Brain Cognitive Development Study, a longitudinal US cohort followed from 2018 to 2024. Parents reported smartphone ownership at 12, which about 70% did; adolescents reported symptoms at 12 and 14. Models adjusted for demographics, household income, pubertal status, body weight, baseline attention and depressive symptoms, parental monitoring, other devices owned, and, in the longitudinal analysis, symptoms already present at 12. 

The American Academy of Pediatrics encourages families to delay and individualize a first smartphone and offers its Family Media Plan as a structuring tool, guidance this study underscores. Regulators have gone further abroad: Australia set a minimum age of 16 for social media accounts as of December 2025. The research agenda the authors lay out is specific, testing whether newly acquiring a phone shifts symptom risk and which of the suspected pathways, social media exposure, sleep disruption, or body-image processes, carries the association. 

Source: Nagata JM, et al. (2026 Sep 25) JAMA Netw Open. Smartphone Ownership and Eating Disorder Symptoms in Early Adolescence