We found an association between digital technology use and BMI in teenagers. Generally, participants with lower socioeconomic status reported more use of digital technology. Controlling for socioeconomic status, internet use on mobile phones for more than 3 hours per day was associated with higher BMI z scores* and greater odds of being overweight, compared with low use (≤30 minutes). Similar associations were found between video gaming and BMI z scores and being overweight. The BMI z score was more strongly related to weekday digital technology use (internet use on mobile phones and video gaming) than weekend use. This association was only partly explained by insufficient sleep, suggesting that there may be other factors affecting the relationship between digital technology use and BMI. Further research which examines changes over time could help us understand the direction of these relationships.
*BMI z score describes how far above or below average a child/young person’s BMI is for their age.