Smartphone Age Eating Disorder Study: What the ABCD Data Shows

Kids who owned a smartphone at 12 were about 1.5 times as likely to report at least one eating-disorder symptom two years later, according to a September 2026 study in JAMA Network Open. That is the core of the new smartphone age eating disorder finding, and it has been shared widely. What it does not show is that a phone causes an eating disorder. The study followed 8,957 children in the Adolescent Brain Cognitive Development (ABCD) Study, the largest long-term study of brain development in US kids. It compared owners and non-owners at 12 and again at 14, after adjusting for family and background differences. The result is a signal worth taking seriously. It is also one data point, about symptoms rather than diagnoses, and the authors say plainly that they do not yet know the mechanism. Here is how to read it, and what to do at home this week.

Key Takeaways

• Owning a smartphone at 12 was linked to higher risk at 14 of binge-eating symptoms (risk ratio 1.67), behaviors aimed at preventing weight gain (1.50), tying self-worth to weight (2.03) and any eating-disorder symptom (1.49).
• The study measured symptoms reported on questionnaires, not clinical diagnoses, and it is observational. It cannot show the phone caused anything.
• A separate 2026 Pediatrics study of the same cohort linked phone ownership at 12 to depression, obesity and insufficient sleep, so the eating-disorder finding sits inside a wider pattern.
• The AAP says no specific age has been shown to be safe for a first phone; readiness matters more than a birthday.
• Early help works. Warning signs are behavioral and visible: skipped meals, rigid food rules, secret eating, pulling away from friends, harsh talk about body shape.

If you are worried right now: In the US, call or text 988 (Suicide & Crisis Lifeline) or text HOME to 741741 (Crisis Text Line). For eating-disorder support and referrals, the ANAD helpline is 1-888-375-7767 (weekdays, 9 a.m. to 9 p.m. Central). Outside the US, find a local line at findahelpline.com. In an emergency, call 911. Your child’s pediatrician is also a good first call.

What the Smartphone Age Eating Disorder Study Found

The study, “Smartphone Ownership and Eating Disorder Symptoms in Early Adolescence,” was led by Jason Nagata at the University of California, San Francisco, and published in JAMA Network Open in September 2026. It used ABCD data collected from 2018 to 2024 at 21 US sites. Of the 8,957 participants, 6,225 (69.5%) owned a smartphone at age 12.

The researchers looked at five symptoms, each scored yes or no: binge-eating symptoms, behaviors meant to prevent weight gain after eating (the paper calls these “inappropriate compensatory behaviors”), worry about weight gain, self-worth tied to weight, and any eating-disorder symptom at all.

They ran two kinds of analysis. The first was a snapshot at 12. Owners were more likely than non-owners to report binge-eating symptoms (prevalence ratio 1.61), self-worth tied to weight (2.21) and any symptom (1.36). The second was the one that got the headlines: owning a phone at 12 and symptoms two years later, at 14.

That longitudinal result held for four of the five measures after adjustment for covariates:

• binge-eating symptoms: risk ratio 1.67
• compensatory behaviors: 1.50
• self-worth tied to weight: 2.03
• any eating-disorder symptom: 1.49

Worry about weight gain is the one measure the abstract does not list among the significant two-year results.

The authors’ conclusion is careful: smartphone ownership “was associated with a variety of ED symptoms, suggesting that the timing of smartphone ownership may be associated with ED risk,” and “future research is needed to characterize the mechanisms underlying these observed associations.” Note the verb. Associated.

How to Read a Risk Ratio Without Panicking

A risk ratio compares two groups. A ratio of 1.49 means owners had about 49% higher relative risk of reporting a symptom than non-owners. It does not mean 49% of owners had symptoms.

A made-up example makes the difference clear. If 10 of every 100 non-owners reported a symptom, a ratio of 1.49 would put owners at roughly 15 of every 100. That is a real difference across thousands of kids. For one child, most of the story is still everything else in their life.

Three limits matter for parents:

Symptoms are not diagnoses. A yes on a questionnaire item is a flag, not a clinical eating disorder. Some of those kids will be fine; some will need care.

Observational designs can’t rule out other explanations. Families who hand over a phone at 12 may differ in ways the models didn’t fully capture: schedules, stress, older siblings, how much unsupervised time a child has. The researchers adjusted for many of these, but adjustment is never complete.

The mechanism wasn’t tested. The paper does not say which part of owning a phone matters. The AAP’s 2026 guidance offers a plausible lead: it warns that for teens, “algorithms and designs can also expose them to inappropriate content that promotes self-harm or eating disorders.” Sleep is another candidate. Neither was measured in this study.

The Wider ABCD Pattern: Sleep, Mood and Weight

The eating-disorder paper is not alone. In January 2026, Ran Barzilay and colleagues at Children’s Hospital of Philadelphia published a Pediatrics study of 10,588 ABCD participants. At 12, phone owners had higher odds of depression (odds ratio 1.31), obesity (1.40) and insufficient sleep (1.62) than non-owners. Each earlier year of getting a phone was linked to slightly higher odds of obesity and insufficient sleep.

The most interesting part is the follow-up. Among kids with no phone at 12, those who got one in the next year had higher odds at 13 of clinical-level mental-health symptoms (1.57) and insufficient sleep (1.50) than those who still didn’t have one, even after controlling for their earlier mental health and sleep. The models also adjusted for parental monitoring and other devices.

Put the two papers together and a picture forms. Early phone ownership travels with worse sleep, more mood problems and more body-related distress. None of these studies proves the phone is the cause. But they point in the same direction, and sleep is the thread a parent can most easily pull.

Warning Signs and What the Study Measured

This table pairs the study’s measures with what a parent might actually notice. The warning signs come from the Mayo Clinic’s guidance on eating disorders and the National Institute of Mental Health, not from the ABCD paper itself.

What the study measured	Linked risk at 14 (phone at 12)	What a parent might notice
Binge-eating symptoms	1.67×	Eating in secret, hidden food wrappers, distress or shame after eating
Behaviors to prevent weight gain	1.50×	Leaving right after meals, intense or compulsive exercise, refusing rest days
Self-worth tied to weight	2.03×	Constant body checking, mood that rises or falls with appearance
Worry about weight gain	not listed as significant	Frequent talk about being “unhealthy” or needing to lose weight
Any symptom	1.49×	Skipping meals with excuses, rigid food rules, eating apart from the family, pulling away from friends

One honest caveat about the table: the middle column shows relative risk in a population. It is not a diagnostic score for your child.

The National Institute of Mental Health puts the reason to act early bluntly: eating disorders “are serious and can be life-threatening,” and they “can be treated successfully. Early detection and treatment are important for a full recovery.” For a longer list of signs by age, see our guide to teen eating disorder warning signs.

A Calm Plan for Families With a Phone Decision Ahead (or Behind)

If your child doesn’t have a phone yet, decide on readiness, not age

The AAP’s 2026 guidance says “studies don’t point to a specific age that’s safe,” and suggests looking at whether a child is mostly truthful with adults and handles conflict safely. That is a better test than a birthday. If you want more on the timing research, our explainer on what age kids should get a phone walks through it, and the companion piece on three big first-phone studies compares them side by side.

If your child already has one, protect sleep first

Sleep is the outcome most consistently linked to early phones in ABCD data, and it is the one you can change tonight. Phones charge outside the bedroom. The AAP suggests screen-free bedrooms and no screens in the hour before bed. Present it as a family rule, not a punishment, and follow it yourself.

Turn off the parts of the phone that feed comparison

You don’t need to read every message to shape the feed. Turn off autoplay where you can, use the platform’s teen account settings, and sit with your child to reset the recommendations together. Ask what kind of videos show up when they open the app. If the answer is “what I eat in a day” or body-transformation clips, that is worth a conversation, not a confiscation.

Talk about bodies the boring, neutral way

Kids pick up on adult comments about weight, dieting and “good” or “bad” food. Keep family talk about food practical and about bodies neutral. Praise effort, skill and kindness more than appearance. This matters with or without a phone.

What not to do

Don’t take the phone away as a reaction to this study and call it protection. Sudden confiscation can push a struggling teen toward secrecy, and secrecy is the enemy of early help. And don’t diagnose. If you see warning signs, your next step is the pediatrician, not a lecture.

What to Watch For Over the Next 3 Months

• Week 4: Is your child sleeping more on school nights since the phone left the bedroom? Do meals at home feel normal, with no new rules about what they will or won’t eat?
• Month 2 red flags: Skipping meals with excuses, eating alone or in secret, leaving the table right after eating, exercise that seems compulsive, new harsh comments about their body, dropping friends or activities they used to enjoy.
• Month 3 self-check: Has your child brought up something they saw online about food or bodies? If they haven’t, open the door yourself: “Does your feed show you a lot of body or diet stuff?” If any red flags have shown up, book a pediatrician visit and say exactly what you’ve noticed.

Frequently Asked Questions

Does this study mean phones cause eating disorders?

No. It is an observational cohort study, so it shows that phone ownership at 12 and later symptoms travel together after adjusting for many family factors. It cannot rule out other explanations, and it did not test a mechanism. The authors themselves call for research into why the association exists.

My 11-year-old already has a phone. Should I take it back?

Not because of this study alone. A sudden reversal can damage trust. Better levers are sleep (phone out of the bedroom), feed settings, regular conversations about what they see, and watching for behavioral warning signs. If you see any, talk to your pediatrician rather than relying on the phone rule to fix it.

What are the earliest signs of an eating disorder in kids?

Common early signs include skipping meals with excuses, rigid food rules, eating in secret, frequent negative talk about weight or shape, body checking, compulsive exercise and withdrawing from friends. Signs vary by disorder, and kids of any body size can be affected. Early treatment improves recovery.

Who should I call if I’m worried?

Start with your child’s pediatrician. The ANAD helpline (1-888-375-7767, weekdays) offers support and referrals. If your child talks about self-harm or you fear for their safety, call or text 988 in the US, text HOME to 741741, or call 911. Outside the US, findahelpline.com lists local lines.

Is there a “safe” age for a first smartphone?

The AAP says research doesn’t point to one. The ABCD studies suggest that later and more gradual tends to be associated with better sleep and mood, but readiness, supervision and settings matter as much as the date on the calendar.

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About the author

Ricky Flores is the founder of HiWave Makers and an electrical engineer with 15+ years of experience building consumer technology at Apple, Samsung, and Texas Instruments. He writes about how kids learn to build, think, and create in a tech-saturated world. Read more at hiwavemakers.com.

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Sources

1. Nagata, J. M., Wong, J. H., Talebloo, J., et al. (2026). “Smartphone Ownership and Eating Disorder Symptoms in Early Adolescence.” JAMA Network Open. https://doi.org/10.1001/jamanetworkopen.2026.37897
2. Barzilay, R., Pimentel, S. D., Tran, K. T., et al. (2026). “Smartphone Ownership, Age of Smartphone Acquisition, and Health Outcomes in Early Adolescence.” Pediatrics, 157(1). https://pubmed.ncbi.nlm.nih.gov/41324306/
3. Munzer, T. (2026). “Helping Kids Thrive in a Digital World: AAP Policy Explained.” HealthyChildren.org, American Academy of Pediatrics. https://www.healthychildren.org/English/family-life/Media/Pages/helping-kids-thrive-in-a-digital-world-AAP-policy-explained.aspx
4. American Academy of Pediatrics. (2026). “A Child-Friendly Digital World: AAP Releases New Media Recommendations.” HealthyChildren.org. https://www.healthychildren.org/English/news/Pages/creating-a-child-friendly-digital-world-AAP-releases-new-media-recommendations.aspx
5. National Institute of Mental Health. (n.d.). “Eating Disorders.” NIMH. https://www.nimh.nih.gov/health/topics/eating-disorders
6. Mayo Clinic Staff. (2025). “Eating disorders: Symptoms and causes.” Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/eating-disorders/symptoms-causes/syc-20353603
7. ANAD. (n.d.). “Eating Disorders Helpline.” National Association of Anorexia Nervosa and Associated Disorders. https://anad.org/eating-disorders-helpline/