Association Between Smartphone Usage Time and Dietary Behavior Among Adolescents: Based on the 2022~2023 Korea Youth Risk Behavior Surveys

This study analyzed the association between smartphone usage time and dietary behavior, demographic characteristics, physical activity, and mental health among adolescents. Data from 101,051 adolescents participating in the 18th (2022) and 19th (2023) Korea Youth Risk Behavior Surveys were analyzed. Participants were classified into two groups based on daily smartphone usage: normal (<5 hours/day) and risk (≥5 hours/day). Adjusted odds ratios (AORs) were calculated using a complex samples logistic regression after adjusting for demographic characteristics. The risk group had lower frequencies of fruit consumption, water intake, and breakfast eating consumption but higher frequencies of sweetened beverage and fast food consumption compared to the normal group (p<0.001). Group consuming sweetened beverages more than five times per week were significantly more likely to experience sadness and despair (AOR= 1.20, 95% CI= 1.10-1.31) and loneliness (AOR= 1.35, 95% CI= 1.25-1.46) compared to those consuming them less than once per week (p<0.001). Similarly, consuming fast food more than five times per week significantly increased the odds of sadness and despair (AOR= 1.40, 95% CI= 1.28-1.54), loneliness (AOR= 1.34, 95% CI= 1.22- 1.47), and generalized anxiety disorder (AOR= 1.49, 95% CI= 1.32-1.68). Additionally, group consuming breakfast only 1-2 times per week had significantly higher odds of sadness and despair, suicidal ideation, suicide planning, suicide attempts, and loneliness compared to those consuming it five times per week (p<0.001). In conclusion, reducing smartphone usage time among adolescents may be an effective strategy not only for fostering healthy dietary habits but also for improving physical and mental health.