Overview

• Each extra hour of daily recreational screen time corresponded to a 0.08 standard deviation rise in cardiometabolic risk score for 10-year-olds and 0.13 standard deviations for 18-year-olds.
• Children and adolescents with shorter sleep durations or later bedtimes showed stronger associations between screen time and cardiometabolic risk.
• A machine-learning analysis uncovered a unique “screen-time fingerprint” in blood metabolites, indicating early biological traces of habitual device use.
• The study’s observational design and reliance on self- or parent-reported screen and sleep data preclude causal conclusions and may involve measurement biases.
• Researchers plan to incorporate objective device-usage tracking in extended follow-up of participants entering early adolescence.