Consumption of Ultra-Processed Food and Risk of Non-Alcoholic Fatty Liver Disease: A Prospective Analysis of the Korean Genome and Epidemiology Study

Background: Ultra-processed food (UPF) consumption is widespread and has been linked to obesity, hypertension, and all-cause mortality. However, the relationship between UPF consumption and non-alcoholic fatty liver disease (NAFLD) remains unclear, especially in populations where traditional diets are still dominant but are undergoing a gradual transition. In this study, we investigated the association between UPF consumption and the risk of developing NAFLD among Korean adults.Methods: This cohort study included 44,642 Korean adults aged 40-69 years, utilizing data from the Health Examinees database. Dietary information was collected through a food frequency questionnaire, and UPF were categorized according to the NOVA classification system based on the degree of processing. A multivariable Cox proportional hazards model assessed the association between UPF consumption and NAFLD risk.Findings: Over a 4.2-year follow-up period, 1,562 participants developed NAFLD. After adjusting for potential confounders, higher UPF consumption was associated with a 35% and 48% increased risk of NAFLD in men and women, respectively. Similar results were observed in both continuous and sensitivity analyses. Among the diverse UPF subtypes, ramen consumption showed the strongest adverse association with NAFLD risk in both men and women (hazard ratio = 2.05 (1.59, 2.65) in men; 1.80 (1.48, 2.19) in women).Conclusions: Our findings suggest that higher UPF consumption is linked to an increased risk of NAFLD. Further comprehensive investigations in a broader spectrum of populations are warranted to corroborate and fortify these results. This will contribute to develop NAFLD preventive strategies.Funding: This research was supported by a National Research Foundation of Korea (NRF) grant funded by the Korean government through the Ministry of Science and ICT (MSIT) (grant number: 2022R1F1A1074279).Declaration of Interest: No potential conflicts of interest relevant to declare.Ethical Approval: The Institutional Review Board (IRB) (IRB No. 1041078-20230628-HR-174) and the Ethics Committee of the Korean Health and Genomic Study of the Korean National Institutes of Health approved this study.