A new study reveals that having a smartphone at age 12 may double the likelihood of developing eating-disorder symptoms by age 14, highlighting the importance of timing and content exposure in children’s digital habits.
A new study suggests that ownership of a smartphone at age 12 may be linked to a higher risk of later eating-disorder symptoms, adding to a growing body of evidence that the timing of a child’s first device can matter as much as the amount of time spent online.
Published in JAMA Network Open, the research drew on data from almost 9,000 adolescents in the United States who were followed through the Adolescent Brain Cognitive Development Study, one of the country’s largest long-term health studies of children. The findings showed that 70% of 12-year-olds already had their own phone. Two years later, 24% of those early phone owners reported at least one eating-disorder symptom, compared with less than 16% of teens who had not had a smartphone at 12.
Jason Nagata, the study’s lead author and an associate professor of paediatrics at the University of California, San Francisco, said smartphones can place “a world of appearance-focused content” into a young person’s pocket. He said parents should think not only about whether a child gets a device, but also when that happens, because a phone can broaden access to social media, influencer content and other material that may intensify body dissatisfaction.
The study found that children who had a smartphone at 12 were twice as likely to connect their self-worth to their weight and about 1.5 times as likely to try to control their weight through behaviours such as eating low-calorie foods or exercising excessively. The risk appears especially relevant during the tween years, when puberty and body changes can make young people more sensitive to comparison, Nagata said. He added that the concern is not simply about screen time, but about the kind of content children are exposed to.
That concern is echoed by other research. A systematic review indexed in PubMed found that higher problematic smartphone use and more screen time were linked with body dissatisfaction, emotional eating and food addiction, while another analysis of ABCD data reported that each extra hour of total screen time and social media use was associated with greater odds of eating-disorder symptoms two years later. The CDC has also warned that excessive screen time can be associated with depression, lower self-worth and other negative outcomes for children and teenagers.
Mitch Prinstein, a psychologist at the University of North Carolina at Chapel Hill who was not involved in the study, said delaying phones by six months or a year may benefit some children’s mental health. For families that do decide to hand over a phone, he suggested gradual access to social media rather than an unrestricted device. Nagata also recommended practical guardrails, including limiting app downloads, keeping phones out of the bedroom and maintaining open conversations about what children are seeing online and how they feel about their bodies. He said mealtimes, when phones are already off the table in many homes, can be a useful moment to talk.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
