By the time many children reach middle school, getting a smartphone can feel almost inevitable. It’s how they talk to friends, coordinate with family, watch videos, play games, and increasingly, experience the social world around them.
But new research raises questions about what early access to that world could mean for the way young people think about food and their bodies.
A large U.S. study published in JAMA Network Open followed 8,957 adolescents and found that children who owned smartphones at age 12 were more likely to report eating disorder symptoms two years later.
By age 14, 24.2% of those who had a smartphone at 12 reported at least one symptom, compared with 15.5% of those who didn’t.
Those symptoms included binge eating, extreme attempts to control weight, compensatory behaviors such as excessive exercise, and basing self-worth on body weight.
The findings don’t prove that smartphones cause eating disorders. But with about 70% of the children in the study already owning a smartphone at age 12, they raise an important question for families: what happens when access to social comparison, appearance-focused content, diet culture, and other online influences begins during a particularly sensitive stage of adolescence?
Smartphones at 12 Were Linked to More Symptoms at 14
The September 2026 study used data from the Adolescent Brain Cognitive Development Study, or ABCD Study, a large, long-running U.S. research project following children through adolescence.
Researchers led by the University of California, San Francisco examined both smartphone ownership and eating disorder symptoms at ages 12 and 14.
At age 12, approximately 70% of the participants already owned smartphones.
Two years later, 24.2% of those early smartphone owners reported at least one eating disorder symptom. Among children who had not owned a smartphone at 12, the figure was 15.5%.
That’s a difference of almost nine percentage points.
After researchers accounted for a number of other factors, smartphone ownership at age 12 was associated with a 49% higher risk of reporting at least one eating disorder symptom at 14. It was also associated with a 67% higher risk of binge-eating symptoms, a 50% higher risk of inappropriate behaviors intended to prevent weight gain, and roughly twice the risk of tying self-worth to body weight.
Because researchers followed the same children over time rather than simply comparing two groups at a single point, they were able to examine whether earlier smartphone ownership was associated with later symptoms.
But there’s an important word there: associated. The researchers did not randomly give smartphones to some children and withhold them from others. That means the study can identify a relationship between smartphone ownership and eating disorder symptoms, but it cannot establish that the phones themselves caused those symptoms.
What Counts as an Eating Disorder Symptom?
The study did not find that nearly one-quarter of smartphone-owning children had been diagnosed with an eating disorder.
It measured symptoms and behaviors associated with disordered eating, which is an important distinction.
These included binge eating, inappropriate compensatory behaviors intended to prevent weight gain, worrying about weight gain, and placing excessive importance on body weight when evaluating self-worth.
Some of these behaviors can eventually form part of a diagnosable eating disorder, while others may occur without someone meeting the full clinical criteria for one.
That doesn’t make them meaningless.
Eating disorders are serious mental and physical health conditions, and problematic relationships with food and body image can begin well before someone receives a formal diagnosis. Recognizing concerning changes early can provide an opportunity for families and healthcare professionals to intervene before patterns become more entrenched.
Why Might Smartphones Matter?
A smartphone is ultimately just a device. The bigger question is what it gives a child access to.
The study authors point to several possible pathways, including social media exposure, body-image processes, and sleep disruption.
Before smartphones and social media, adolescents certainly compared themselves with friends, classmates, celebrities, and images in magazines and television. Smartphones dramatically expand the number of people and images available for comparison.
A child can now move from looking at classmates to scrolling through hundreds of carefully selected, edited, filtered, or commercially promoted bodies within minutes.
Social media feeds can also expose young users to dieting content, weight-loss transformations, fitness influencers, “what I eat in a day” videos, calorie tracking, and other material that places considerable attention on appearance and food.
That may be especially relevant around puberty.
Early adolescence is already a period of rapid physical development. It’s also a time when peer acceptance becomes increasingly important while social and emotional development is still underway.
However, the researchers did not measure the content children were viewing on their smartphones, so the study cannot tell us whether social media, appearance-focused posts, algorithms, or any particular type of content explains the association.
Those remain possible explanations that require further research.
It May Not Be Just About Social Media
There are other ways smartphones could potentially influence eating and body image.
One proposed pathway involves sleep.
Late-night phone use can interfere with sleep, while inadequate sleep can affect mood, emotional regulation, and other aspects of health. The researchers therefore identified sleep disruption as another possible mechanism worth investigating.
Smartphone ownership can also mean very different things from one household to another.
One 12-year-old might have a phone primarily for calling parents and messaging friends, with restrictions on apps and nighttime use. Another might have unrestricted access to multiple social platforms for hours every day.
Simply asking whether a child “owns a smartphone” can’t capture all of those differences.
In fact, the researchers specifically identified this as a limitation: smartphone ownership did not tell them what children were viewing or how they were using their devices.
That’s another reason the study shouldn’t be interpreted as evidence that the physical device itself is responsible for eating disorder symptoms.
Eating Problems Among Young People Were Already a Concern
The new findings also land against a much larger problem.
A 2023 systematic review and meta-analysis published in JAMA Pediatrics examined 32 studies involving more than 63,000 children and adolescents across 16 countries.
Researchers estimated that approximately 22% screened positive for disordered eating, although prevalence varied considerably between groups.
In other words, concerns about food and body image among young people did not begin with smartphones.
Eating disorders can develop through a complicated combination of genetic, psychological, social, environmental, and biological factors. There isn’t a single cause that explains why one child develops an eating disorder and another doesn’t.
Smartphones may represent another increasingly important part of that environment.
The Study Doesn’t Prove Smartphones Cause Eating Disorders
This distinction is particularly important for parents reading numbers like 24.2% versus 15.5%.
The study was observational.
Families who give their children smartphones earlier may differ from families who wait. The researchers accounted for numerous potential confounding factors, but they acknowledged that unmeasured differences could still have influenced the results.
Other factors associated with eating disorders, including bullying, neurodevelopmental conditions, and existing or emerging mental health problems, were not fully captured in the analysis.
The eating disorder symptoms were also reported by the adolescents themselves rather than determined through clinical diagnoses.
And the researchers did not establish a particular age at which giving a child a smartphone becomes safe or unsafe.
So the takeaway isn’t that giving a 12-year-old a phone will cause an eating disorder.
Instead, the findings suggest that the timing of smartphone ownership may be another factor worth considering as children enter adolescence.
Read More: Woman Tells Story About How Her Smartphone ‘Ruined Her Life’
Warning Signs Parents Can Watch For
Rather than focusing exclusively on the number of hours a child spends looking at a screen, parents may find it useful to pay attention to changes in how their child talks and behaves around food, exercise, and their body.
Potential warning signs can include skipping meals, increasingly rigid food rules, extreme dieting, eating unusually large amounts of food while feeling unable to stop, hiding food, or exercising compulsively.
Changes in body image can matter too. A child who suddenly becomes preoccupied with weight, repeatedly compares their appearance with people online, expresses intense dissatisfaction with their body, or begins tying their self-worth to a number on a scale may need additional support.
Not every teenager who worries about appearance has an eating disorder. Adolescence can bring plenty of insecurity on its own.
But persistent or escalating changes are worth taking seriously, particularly when they begin affecting eating, social life, mood, or physical health.
A pediatrician or other qualified healthcare professional can help determine whether further evaluation is needed.
What Can Families Do About Smartphone Use?
The researchers aren’t recommending that every family keep smartphones away from children until a particular birthday.
Families have different reasons for giving children phones, including safety, transportation, school, communication, and coordinating increasingly independent schedules.
Instead, the study authors suggest that parents and caregivers consider age-appropriate limits and supervision when children first gain independent access to smartphones.
That can mean knowing which apps a child uses, establishing boundaries around nighttime and mealtime phone use, and having conversations about what appears in their feeds.
Those conversations can go beyond simply warning that “social media is bad.”
Parents can talk about how influencer content is selected and edited, why algorithms tend to show more of whatever keeps someone watching, and why an image receiving thousands of likes doesn’t make the body, diet, or lifestyle shown in it realistic or healthy.
It can also be worth simply asking: How does the content you see online make you feel about yourself?
That question may reveal more than a screen-time counter ever could.
Read More: When ‘Clean Eating’ Becomes an Obsession: The Risks No One Talks About
Smartphones Aren’t Going Away
Smartphones are now a normal part of adolescence, which is precisely what makes these findings worth paying attention to. About 70% of the children in this study already had one by age 12.
The research doesn’t show that handing a 12-year-old a phone will cause an eating disorder, nor does it identify an age at which smartphone ownership suddenly becomes safe.
What it does show is a meaningful association worth investigating: children who already had smartphones at 12 were more likely to report eating disorder symptoms two years later than children who did not.
For parents, that shifts the conversation beyond simply counting hours of “screen time.” What children are seeing, who they’re comparing themselves with, and how those experiences affect the way they think about food and their bodies may matter just as much as how long they’re holding the phone.
As researchers work to understand what’s driving the association, families don’t have to wait for a definitive answer to start talking about those things.
Disclaimer: The information provided here is for educational and informational purposes only and is not a substitute for professional psychological, psychiatric, or medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare professional with questions or concerns about a child’s physical or mental health. Never ignore professional advice or delay seeking support because of information contained herein
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.
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