Weight Status, Dietary Behaviors, and Health and Psychological Characteristics Among Korean Adolescents: A Nationwide Cross-Sectional Study

Background/Objectives: This study examined associations between dietary behaviors, weight status, and health and psychological indicators among Korean adolescents. Methods: Data from 52,618 participants in the 2025 Korea Youth Risk Behavior Survey were analyzed using complex survey methods. Eleven dietary behaviors and four health and psychological indicators were assessed. Survey-weighted descriptive analyses, Rao–Scott chi-square tests, weighted mean comparisons, and covariate-adjusted multinomial logistic regression were performed. Multiple comparisons were addressed using Benjamini–Hochberg false discovery rate (FDR) correction. Results: Dietary behaviors differed across weight status groups, while health and psychological indicators varied across dietary categories. Of 198 regression comparisons, 80 remained significant after FDR correction. Daily breakfast consumption was associated with higher odds of underweight (aOR = 1.265) but lower odds of overweight (aOR = 0.803) and obesity (aOR = 0.861). Higher fruit consumption was associated with lower odds of obesity, whereas zero-calorie beverage consumption was associated with higher odds of obesity (aOR = 1.319–1.951). Consuming at least five cups of water daily was associated with higher odds of obesity (aOR = 2.541). Late-night eating showed inverse associations with overweight and obesity. Conclusions: Dietary behaviors showed distinct associations with weight status and health-related indicators. These cross-sectional findings support considering dietary and sociodemographic differences in adolescent health promotion.