Excessive screen time linked to obesity in US preteen
June 28, 2021
by University of Toronto
A new national study finds that children in the United States with greater screen time usage at ages 9-10 are more likely to gain weight one year later.
The study, publishing in Pediatric Obesity on June 28, found that each additional hour spent on virtually all forms of screen time was associated with a higher body mass index (BMI) one year later. In particular, researchers found that each extra hour spent watching or streaming television, YouTube videos, video games, video chat, and texting led to a higher risk of weight gain one year later. At the start of the study, 33.7% of children were considered overweight or obese, and this increased to 35.5% one year later, a proportion that is expected to rise in the late teens and early adulthood.
BMI is calculated based on height and weight. Researchers analyzed the BMI z-scores, which is relative weight adjusted for a child's age and sex, of 11,066 preteens who are part of the Adolescent Brain Cognitive Development Study, the largest long-term study of brain development in the United States. The children answered questions about their time spent on six different screen time modalities, including television, social media, and texting.
