Why Giving a 12-Year-Old a Smartphone Raises Eating Risks

Handing a 12-year-old a smartphone can feel like unlocking a new world. But sometimes that world brings more than apps and games—it brings images, comparisons, and pressures that can reshape how a child thinks about their body.

A recent U.S. study of roughly 9,000 adolescents found that kids who owned a personal smartphone at age 12 were more likely, by age 14, to report symptoms linked to eating disorders than their peers who did not. About 24 percent of 12-year-olds with phones had at least one symptom by 14, while fewer than 16 percent of those without phones did.

The researchers looked at signs such as binge eating, disrupted sleep, and efforts to control weight with harmful strategies—extreme calorie restriction or excessive exercise among them. Nearly 70 percent of the 12-year-olds in the dataset already had a personal smartphone, underscoring how widespread early ownership has become.

Statistically speaking, children who had a phone at 12 were roughly twice as likely to tie their self-worth to their weight. They were also about 1.5 times more likely to report taking extreme steps to control their weight, compared with those who didn’t have a phone at that age.

What explains the link? The study’s authors point to exposure. A smartphone is more than hardware: it’s a gateway to feeds full of curated images, influencer content and filtered bodies. For a preteen navigating the physical and emotional turbulence of puberty, that stream of appearance-focused material can amplify insecurities and normalize unhealthy behaviors.

This fits into a broader pattern. Earlier research has associated receiving a smartphone before age 12 with higher risks of depression, obesity and insufficient sleep. Eating disorders and disordered eating behaviors often begin quietly—preoccupation with food or weight, distorted body perception, food restriction or compensatory actions like excessive exercise or purging.

Parents and guardians should pair early phone ownership with active supervision, clear rules and conversations about online content and body image.

Practical steps suggested by the researchers include setting explicit rules for device use, talking openly about the types of content children encounter online, keeping phones out of bedrooms at night, limiting which apps a child can install, and designating phone-free times or places. Rather than prescribing a single “right” age to hand over a device, the study emphasizes ongoing parental involvement and watching for changes in eating habits or how a child speaks about their body and weight.

The findings were published in JAMA Network Open and reported by outlets including CNN. The takeaway is simple and unsettling: a small, everyday object can alter a child’s digital environment in ways that affect mental health—so the conversation about smartphones for preteens needs to be as much about supervision and boundaries as it is about the device itself.