Association Between Ultra-Processed Food Consumption and Frailty in Korean Older Adults

Background/Objectives: Population aging is accelerating worldwide, and frailty has emerged as an important health concern among older adults. Although ultra-processed food (UPF) consumption has been associated with a range of adverse health outcomes, evidence on its relationship with frailty among Korean older adults remains limited. This study examined the cross-sectional association between the proportion of total energy intake derived from UPFs and frailty among Korean adults aged 65 years or older. Methods: We analyzed data from 9861 adults aged ≥65 years who participated in the 2014–2019, 2022, and 2024 Korea National Health and Nutrition Examination Survey cycles, in which the variables required to assess frailty were available. Dietary intake was assessed using a 24-h dietary recall, and foods were classified according to the NOVA food classification system. Frailty was defined using a modified Fried frailty phenotype. Survey-weighted multivariable logistic regression models were used to examine associations between UPF energy contribution and frailty, and restricted cubic spline models were used to evaluate the dose–response relationship. Results: In the fully adjusted model, participants in the highest quartile of UPF energy contribution had 31% higher odds of frailty than those in the lowest quartile (odds ratio [OR] = 1.31, 95% confidence interval [CI]: 1.08–1.59; p for trend = 0.002). Among the individual frailty components, participants in the highest quartile also had higher odds of low physical activity (OR = 1.31, 95% CI: 1.13–1.51; p for trend = 0.001). Restricted cubic spline analysis showed no evidence of a nonlinear association between UPF energy contribution and frailty (p for nonlinearity = 0.8). Conclusions: Higher UPF consumption was positively associated with frailty among Korean older adults, particularly with low physical activity. These findings highlight the relevance of UPF consumption to frailty in an older population with relatively low levels of UPF intake.