{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T14:00:09Z","timestamp":1789999209309,"version":"4.0.1"},"reference-count":43,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T00:00:00Z","timestamp":1789862400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nutrients"],"abstract":"<jats:p>Background\/Objectives: Diet quality is a leading modifiable determinant of non-communicable disease, yet its upstream, person-level determinants are seldom studied. We examined whether health literacy is associated with overall diet quality in a nationally representative Korean sample. Methods: This cross-sectional study analyzed 5353 adults aged \u226519 years from the 2024 Korea National Health and Nutrition Examination Survey. Health literacy, measured with a validated 10-item instrument, was analyzed as score-based categories, continuously, and as the official binary indicator; diet quality was the Korean Healthy Eating Index (KHEI, 0\u2013100) from a single 24 h recall. Survey-weighted linear and logistic regression was used, with component, subgroup, sensitivity, and multiple imputation analyses. Results: The crude difference between the lowest (\u226428 points) and highest (\u226533 points) categories was positive (\u03b2 = +1.41); adjustment for age alone inverted it (\u03b2 = \u22122.76), and the fully adjusted difference was \u03b2 = \u22121.70 (95% CI, \u22122.66 to \u22120.75; \u22120.13 SD), with higher odds of lowest tertile diet quality (OR = 1.37; 95% CI, 1.09 to 1.72; p = 0.007). Each 1-SD increment in health literacy corresponded to \u03b2 = +0.77 (95% CI, 0.42 to 1.12). Component differences were negative for 12 of 14, but none survived false discovery rate correction. The association was more evident in men (women vs. men, interaction \u03b2 = \u22121.03 per 1-SD increment; 95% CI, \u22121.67 to \u22120.40). Multiple imputation (m = 20; n = 5678) gave consistent estimates. Conclusions: Lower health literacy was associated with modestly poorer diet quality, an association masked and reversed by age until adjustment. The cross-sectional design precludes causal inference, the single-day assessment may not represent habitual intake, and component and subgroup findings are exploratory.<\/jats:p>","DOI":"10.3390\/nu18183082","type":"journal-article","created":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T12:50:03Z","timestamp":1789995003000},"page":"3082","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Lower Health Literacy Is Associated with Poorer Diet Quality in Korean Adults: An Association Masked by Age"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2791-158X","authenticated-orcid":false,"given":"Hyunjoo","family":"Joo","sequence":"first","affiliation":[{"name":"Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan 31116, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"software","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8661-493X","authenticated-orcid":false,"given":"Jonghyuk","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Preventive Medicine, College of Medicine, Dankook University, Cheonan 31116, Republic of Korea"},{"name":"Research Institute of Healthcare Bigdata, College of Medicine, Dankook University, Cheonan 31116, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,20]]},"reference":[{"key":"ref_1","unstructured":"GBD 2017 Diet Collaborators (2019). Health effects of dietary risks in 195 countries, 1990\u20132017: A systematic analysis for the Global Burden of Disease Study 2017. Lancet, 393, 1958\u20131972."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e133","DOI":"10.3346\/jkms.2025.40.e133","article-title":"Trends in Diet Quality by the Diagnosis of Chronic Diseases in Korea, 2013\u20132021: A Nationwide Representative Study","volume":"40","author":"Lee","year":"2025","journal-title":"J. Korean Med. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"e2218297","DOI":"10.1001\/jamanetworkopen.2022.18297","article-title":"Trends in Diet Quality and Cardiometabolic Risk Factors Among Korean Adults, 2007\u20132018","volume":"5","author":"Jo","year":"2022","journal-title":"JAMA Netw. Open"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1093\/heapro\/15.3.259","article-title":"Health literacy as a public health goal: A challenge for contemporary health education and communication strategies into the 21st century","volume":"15","author":"Nutbeam","year":"2000","journal-title":"Health Promot. Int."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"S\u00f8rensen, K., Van den Broucke, S., Fullam, J., Doyle, G., Pelikan, J., Slonska, Z., and Brand, H. (2012). Health literacy and public health: A systematic review and integration of definitions and models. BMC Public Health, 12.","DOI":"10.1186\/1471-2458-12-80"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"97","DOI":"10.7326\/0003-4819-155-2-201107190-00005","article-title":"Low health literacy and health outcomes: An updated systematic review","volume":"155","author":"Berkman","year":"2011","journal-title":"Ann. Intern. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1012","DOI":"10.1016\/j.jada.2011.04.010","article-title":"Health Literacy Is Associated with Healthy Eating Index scores and sugar-sweetened beverage intake: Findings from the rural Lower Mississippi Delta","volume":"111","author":"Zoellner","year":"2011","journal-title":"J. Am. Diet. Assoc."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Duarte, A., Martins, J., Lopes, C., Silva, M.J., Augusto, C., Martins, S.P., and Ros\u00e1rio, R. (2024). Health literacy and its association with the adoption of the Mediterranean diet: A cross-sectional study. Nutrients, 16.","DOI":"10.3390\/nu16142176"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1177\/10901981221079742","article-title":"Health literacy, numeracy, and Dietary Approaches to Stop Hypertension accordance among hypertensive adults","volume":"50","author":"Lou","year":"2023","journal-title":"Health Educ. Behav."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2680","DOI":"10.1017\/S1368980017001483","article-title":"Health literacy and fruit and vegetable intake in rural Australia","volume":"20","author":"Lim","year":"2017","journal-title":"Public Health Nutr."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Tian, X., Hu, X., Sun, Y., and Liu, H. (2025). Gender, residence, and socioeconomic differences in the relationship of nutrition literacy with vegetable and fruit intake in adults. Front. Nutr., 12.","DOI":"10.3389\/fnut.2025.1606315"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Steinke, E.-M., Hucke, B., Rohmann, M., Tietz, F., Lewejohann, J.-C., and Nuernberger, M. (2026). The relationship between health literacy, food literacy, and dietary choices\u2014A systematic review. Front. Public Health, 14.","DOI":"10.3389\/fpubh.2026.1769299"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1713","DOI":"10.1017\/S0007114514000087","article-title":"Relationship between nutrition knowledge and dietary intake","volume":"111","author":"Spronk","year":"2014","journal-title":"Br. J. Nutr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"382","DOI":"10.4162\/nrp.2021.15.3.382","article-title":"Trends in sodium intake and major contributing food groups and dishes in Korea: The Korea National Health and Nutrition Examination Survey 2013\u20132017","volume":"15","author":"Jeong","year":"2021","journal-title":"Nutr. Res. Pract."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"558","DOI":"10.5720\/kjcn.2016.21.6.558","article-title":"A Comparison of Sources of Sodium and Potassium Intake by Gender, Age and Regions in Koreans: Korea National Health and Nutrition Examination Survey (KNHANES) 2010\u20132012","volume":"21","author":"Park","year":"2016","journal-title":"Korean J. Community Nutr."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Cheung, J.T.H., Lok, J., Gietel-Basten, S., and Koh, K. (2021). The food environments of fruit and vegetable consumption in East and Southeast Asia: A systematic review. Nutrients, 13.","DOI":"10.3390\/nu13010148"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Carmona, B.A., Gomez, V., Oke, S.A., Reyes, L.I., and Bellows, L.L. (2026). The Relationship between Health Literacy, Nutrition Literacy, and Food Literacy and Dietary Behaviors in Adults: A Systematic Review. Nutr. Rev., nuag041.","DOI":"10.1093\/nutrit\/nuag041"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1795","DOI":"10.1017\/S000711452300082X","article-title":"Associations of food choice values and food literacy with overall diet quality: A nationwide cross-sectional study in Japanese adults","volume":"130","author":"Murakami","year":"2023","journal-title":"Br. J. Nutr."},{"key":"ref_19","first-page":"709","article-title":"Development of a health literacy measurement tool for the Korea National Health and Nutrition Examination Survey","volume":"16","author":"Yoon","year":"2023","journal-title":"Public Health Wkly. Rep."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"e2024061","DOI":"10.4178\/epih.e2024061","article-title":"Development and validation of the Health Literacy Index for the Community for the Korean National Health and Nutrition and Examination Survey","volume":"46","author":"Yoon","year":"2024","journal-title":"Epidemiol. Health"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e2025037","DOI":"10.4178\/epih.e2025037","article-title":"Health literacy in Korea: Findings from the 2023 Korea National Health and Nutrition Examination Survey","volume":"47","author":"Choi","year":"2025","journal-title":"Epidemiol. Health"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"419","DOI":"10.4163\/jnh.2015.48.5.419","article-title":"Development of Korean Healthy Eating Index for adults using the Korea National Health and Nutrition Examination Survey data","volume":"48","author":"Yook","year":"2015","journal-title":"J. Nutr. Health"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"233","DOI":"10.4162\/nrp.2022.16.2.233","article-title":"Development of the Korean Healthy Eating Index for adults, based on the Korea National Health and Nutrition Examination Survey","volume":"16","author":"Yun","year":"2022","journal-title":"Nutr. Res. Pract."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1093\/ije\/dyt228","article-title":"Data Resource Profile: The Korea National Health and Nutrition Examination Survey (KNHANES)","volume":"43","author":"Kweon","year":"2014","journal-title":"Int. J. Epidemiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1086","DOI":"10.1093\/jnci\/djr189","article-title":"Dealing with dietary measurement error in nutritional cohort studies","volume":"103","author":"Freedman","year":"2011","journal-title":"J. Natl. Cancer Inst."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"606","DOI":"10.1046\/j.1525-1497.2001.016009606.x","article-title":"The PHQ-9: Validity of a brief depression severity measure","volume":"16","author":"Kroenke","year":"2001","journal-title":"J. Gen. Intern. Med."},{"key":"ref_27","first-page":"156","article-title":"Evaluating effect size in psychological research: Sense and nonsense","volume":"2","author":"Funder","year":"2019","journal-title":"Adv. Methods Pract. Psychol. Sci."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1111\/j.2517-6161.1995.tb02031.x","article-title":"Controlling the false discovery rate: A practical and powerful approach to multiple testing","volume":"57","author":"Benjamini","year":"1995","journal-title":"J. R. Stat. Soc. Ser. B Methodol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"b2393","DOI":"10.1136\/bmj.b2393","article-title":"Multiple imputation for missing data in epidemiological and clinical research: Potential and pitfalls","volume":"338","author":"Sterne","year":"2009","journal-title":"BMJ"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"965","DOI":"10.1093\/jssam\/smz036","article-title":"Multiple imputation with survey weights: A multilevel approach","volume":"8","author":"Quartagno","year":"2020","journal-title":"J. Surv. Stat. Methodol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"32297","DOI":"10.1038\/s41598-025-08705-9","article-title":"Cross-sectional analysis of sociodemographic factors associated with self-reported and knowledge-based health literacy in Korea using data from KNHANES 2023","volume":"15","author":"Huh","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Kwon, D.H., and Kwon, Y.D. (2025). Patterns of health literacy and influencing factors differ by age: A cross-sectional study. BMC Public Health, 25.","DOI":"10.1186\/s12889-025-22838-6"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1186\/1742-7622-5-2","article-title":"Simpson\u2019s Paradox, Lord\u2019s Paradox, and Suppression Effects are the same phenomenon\u2014The reversal paradox","volume":"5","author":"Tu","year":"2008","journal-title":"Emerg. Themes Epidemiol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Kirbi\u0161, A., Branilovi\u0107, S., and Lubej, M. (2025). Does health literacy mediate sociodemographic and economic inequalities in fruit and vegetable intake? An analysis of Slovenian national HLS19 survey data. Foods, 14.","DOI":"10.3390\/foods14030378"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1093\/geronb\/gbu161","article-title":"Aging and functional health literacy: A systematic review and meta-analysis","volume":"71","author":"Kobayashi","year":"2016","journal-title":"J. Gerontol. B Psychol. Sci. Soc. Sci."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"e2025062","DOI":"10.4178\/epih.e2025062","article-title":"Age-period-cohort analysis of dietary sodium, potassium, and sodium-to-potassium ratio in Korea","volume":"47","author":"Jun","year":"2025","journal-title":"Epidemiol. Health"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"943","DOI":"10.1111\/jhn.13309","article-title":"Gender differences in diet quality and the association between diet quality and BMI: An analysis in young Australian adults who completed the Healthy Eating Quiz","volume":"37","author":"Fenton","year":"2024","journal-title":"J. Hum. Nutr. Diet."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1207\/s15324796abm2702_5","article-title":"Gender differences in food choice: The contribution of health beliefs and dieting","volume":"27","author":"Wardle","year":"2004","journal-title":"Ann. Behav. Med."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"370","DOI":"10.1177\/1557988314545485","article-title":"Gender differences in health literacy among Korean adults: Do women have a higher level of health literacy than men?","volume":"9","author":"Lee","year":"2015","journal-title":"Am. J. Mens Health"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1093\/ije\/14.1.32","article-title":"Sick individuals and sick populations","volume":"14","author":"Rose","year":"1985","journal-title":"Int. J. Epidemiol."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1111\/jhn.12758","article-title":"Front of pack nutritional labelling schemes: A systematic review and meta-analysis of recent evidence relating to objectively measured consumption and purchasing","volume":"33","author":"Croker","year":"2020","journal-title":"J. Hum. Nutr. Diet."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Devirgiliis, C., Guberti, E., Mistura, L., and Raffo, A. (2024). Effect of fruit and vegetable consumption on human health: An update of the literature. Foods, 13.","DOI":"10.3390\/foods13193149"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Jung, Y.-S., and Joo, H. (2026). Nutritional imbalance and oral functional limitation jointly associated with depressive symptoms in adults living alone: A nationally representative cross-sectional study. Nutrients, 18.","DOI":"10.3390\/nu18132055"}],"container-title":["Nutrients"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/18\/3082\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T13:02:06Z","timestamp":1789995726000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-6643\/18\/18\/3082"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,20]]},"references-count":43,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["nu18183082"],"URL":"https:\/\/doi.org\/10.3390\/nu18183082","relation":{},"ISSN":["2072-6643"],"issn-type":[{"value":"2072-6643","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,20]]}}}