A Smartphone by Age 12 Is Linked to Eating Disorders, New Study Finds

1. Younger smartphone use is associated with more body image issues

Dr. Bennett: One of the things the study suggested is that the younger age at which a child gets their own smartphone, the more opportunity and time there is for unsupervised phone use, including exposure to images of idealized bodies, which has long been linked to worse body image perceptions. 

This research is also nuanced, and one thing we’re learning is that it’s not just about how much time youth are spending online, but how they’re using it. A kid who spends hours online engaged with friends or activities might have better outcomes than someone who spends hours passively scrolling. Passive scrolling has previously been linked to higher rates of anxiety and depression, and the more time spent passively scrolling, the more likely it is that a child could stumble onto pages that encourage them to lose weight, change their appearance or engage in compensatory behaviors, and/or hide symptoms of eating disorders.

If you are able, you can delay smartphone use. You can get your kid a smartwatch or a “dumbphone,” like a flip phone where you can’t scroll, or you can disable features and keep a smartphone on airplane mode or school mode during key points in the day.

Parents can also model good behavior and set screentime limits or designate phone-free times, like family meals. But it’s not as simple as saying that if we got rid of smartphones, we’d all be healthy. We want to use smartphones in balance with everything else that’s important for a kid’s healthy development.

2. The early adolescent brain is more vulnerable

Dr. Bennett: The researchers of this study made the point that different parts of the adolescent brain develop at different rates, which can make teens more vulnerable to social stress, feeling emotionally overwhelmed, preoccupation with body image, and/or impulsive decision making. For example, the parts of our brain that are involved with social connection, social acceptance and emotion are developing at a faster rate than the parts of our brain that are involved in thoughtful decision making and controlling social and emotional urges and behaviors.  

It’s like having a car with a strong engine but weak brakes. At this age, children are more drawn to social acceptance, and it’s somewhat out of balance with how they’re making decisions about their self-worth.

3. Girls are more susceptible, but boys face the same pressures

Dr. Bennett: In analyzing the data by gender, the study found that young girls who owned a smartphone were more worried about weight gain than boys. Early adolescence is when bodies are changing, and part of puberty is dealing with hormones and how they impact our mood and physical development. Girls at this age become more aware of their bodies and potentially more self-conscious, as this study suggests.

But this is not exclusively a girl problem. There’s a huge social media issue right now among young boys and men with “Looksmaxxing,” an online trend that prioritizes physical attractiveness and encourages some unsafe behaviors to achieve a certain body standard. 

Research has found some gender differences in the types of sites kids visit that might be problematic. While it’s not realistic for parents to be constantly looking over their kid’s shoulder to see what they’re doing online, you can have conversations with your children about the types of sites they’re visiting, what they’re seeing and how they interact with people online. When it comes to making decisions about what to post, what sites to visit, and other online behaviors, a good rule of thumb for teens is to pause and think before they post. Parents can suggest the “grandmother rule” to encourage good digital citizenship: don’t share or post anything you wouldn’t say or share in front of your grandmother. 

4. Nighttime phone use and poor sleep raises the risk

Dr. Bennett: The researchers also found that nighttime smartphone use may interrupt sleep, which creates another link to eating disorders. We know that sleep is foundational to our physical and mental health, and when we don’t get enough sleep, it can disrupt our neurochemical and hormonal balances, which impacts our metabolism. As a result, we crave more food and more sugar, and we become more vulnerable to binge eating.

Not sleeping enough can also create further impairments in decision making, so it’s going to be harder to regulate urges and temptations that kids are being faced with online. 

It’s important to keep the smartphone out of your kid’s bedroom at night so they can’t stay up late scrolling and lose sleep.