Relationship Between Fermented Food Consumption Patterns and Hs-CRP Among Middle-Aged Koreans: Data From 2015–2018 Korea National Health and Nutrition Examination

milk).Associations were analyzed using single-and dual-isotope regression models and a novel, k-means clustering analysis of 13C and 15N values.Results: Among adults, regression models revealed associations of 13C values with added sugar intake ( (95% CI): single, 0.17 (-0.01, 0.36); dual, 0.31 (0.10, 0.53)) and with SSB intake (single, 0.30 (0.12, 0.48); dual, 0.31 (0.09, 0.53)), confirming prior findings.Adults in the High 13C-15N cluster consumed more SSB (213 AE 23 kcal/d) on a given day than those in the Low cluster (109 AE 20 kcal/d; p 0.03).In children, no significant associations with added sugar or SSB intake were observed.However, children in the High 13C-15N cluster consumed more cow's milk (81 AE 9 vs. 31 AE 7 kcal/d; p 0.009) and animal protein (408 AE 33 vs. 272 AE 36 kcal/d; p 0.04) than the Low cluster.Children's cow's milk intake was significantly associated with both 13C and 15N values.Conclusions: Age-related differences in children's dietary patterns, especially higher cow's milk consumption, may obscure associations between 13C values and added sugar or SSB intake.These findings emphasize the need to consider age and dietary complexity in biomarker research.