Development of a simplified NOVA-based scoring tool for assessing ultra-processed food consumption among Korean young adults: a cross-sectional study

OBJECTIVES: This study aimed to develop a NOVA-based scoring approach for evaluating ultra- processed food (UPF) intake among Korean adults and to examine its performance. Previous studies have reported that young adults have the highest levels of UPF consumption. Accordingly, this study focused on adults aged 19-40 years and developed scoring components reflecting dietary patterns specific to Korean eating habits. METHODS: Using 24-hour dietary recall data from adults aged 19-40 years in the Korea National Health and Nutrition Examination Survey (2021-2023), foods were classified according to the Korean-adapted NOVA system. The top 10 food groups accounting for ≥ 80% of cumulative UPF-derived energy were selected to construct the scoring components. The tool was operationalized using food frequency questionnaire (FFQ) data from the Gangwon cohort study (2022-2024). Intake frequencies were converted into scores ranging from 0 ("rarely or never") to 5 ("≥ 1 time/day"), and summed to generate the NOVA-UPF score (range: 0-50). RESULTS: Among 237 young adults (aged 20-49 years), the mean NOVA-UPF score was 22.9 ± 8.3. A positive association was observed between the NOVA-UPF score and FFQbased UPF energy intake (Spearman's ρ = 0.629, P < 0.001). Cross-classification showed that 51.9% were classified into the same tertile and 94.9% into the same or adjacent tertiles, with a weighted kappa coefficient of 0.279. CONCLUSION: This NOVA-based scoring approach may serve as a preliminary tool for assessing UPF intake in Korean young adults. Further refinement and rigorous validation using quantitative dietary assessment methods and more diverse populations are required before broader application.