{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T05:23:33Z","timestamp":1787289813158,"version":"build-2736575974"},"reference-count":43,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T00:00:00Z","timestamp":1787097600000},"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: Reliable dietary assessment tools are essential for evaluating dietary habits and diet quality in children. The aim of this study was to assess the reproducibility of a 69-item School Children\u2019s Food Frequency Questionnaire (69-item SCh-FFQ) and the diet quality scores among Polish children aged 7\u20139 years. Methods: The reproducibility study was conducted among 77 children. The 69-item SCh-FFQ was administered twice (test and retest). Data on food consumption frequency were used to evaluate two diet quality scores: the pro-Healthy Diet Index (pHDI) and the non-Healthy Diet Index (nHDI). The reproducibility of the 69-item SCh-FFQ and the diet quality scores was evaluated using comparisons of mean values, cross-classification analysis, Cohen\u2019s kappa statistic, Spearman\u2019s rank correlation coefficient, intraclass correlation coefficient (ICC), and Bland\u2013Altman analysis. Results: No significant differences were observed between test and retest of the FFQ for mean values of the pHDI (2.9 \u00b1 1.8 vs. 2.8 \u00b1 1.9 points; p = 0.124) or the nHDI (4.3 \u00b1 1.5 vs. 4.2 \u00b1 1.5 points; p = 0.611). Total agreement for the classification of children into categories of the diet quality scores reached 81.8% for pHDI and 75.3% for nHDI, with low gross misclassification rates (1.3% and 0.0%, respectively). Cohen\u2019s kappa statistic indicated moderate to good agreement (\u03ba = 0.68 for pHDI and \u03ba = 0.51 for nHDI). For all food items, total agreement ranged from 66.2% to 94.8%, while the kappa statistic ranged from 0.56 to 0.81. Strong correlations and good agreement were observed between repeated measurements for both pHDI (r = 0.748, ICC = 0.778; p &lt; 0.001) and nHDI (r = 0.783, ICC = 0.752; p &lt; 0.001). Bland\u2013Altman analysis demonstrated good agreement and no evidence of proportional bias. Conclusions: The 69-item SCh-FFQ demonstrated satisfactory reproducibility for assessing food consumption frequency and diet quality scores in children aged 7\u20139 years. Therefore, this questionnaire is a promising tool for future epidemiological studies among early school-aged children, although its utility should be confirmed in further validation studies using an appropriate reference method.<\/jats:p>","DOI":"10.3390\/nu18162712","type":"journal-article","created":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T16:12:58Z","timestamp":1787155978000},"page":"2712","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Reproducibility of a 69-Item School Children\u2019s Food Frequency Questionnaire (69-Item SCh-FFQ) and Diet Quality Scores Among Polish Children Aged 7\u20139 Years"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4246-6944","authenticated-orcid":false,"given":"Kamila","family":"Soba\u015b","sequence":"first","affiliation":[{"name":"Institute of Health Sciences, Medical College, Jan Kochanowski University, 5 \u017beromskiego Street, 25-369 Kielce, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1981-7320","authenticated-orcid":false,"given":"Joanna","family":"Kowalkowska","sequence":"additional","affiliation":[{"name":"Department of Human Nutrition, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, 45F Sloneczna Street, 10-718 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3063-0380","authenticated-orcid":false,"given":"Edyta","family":"Suliga","sequence":"additional","affiliation":[{"name":"Institute of Health Sciences, Medical College, Jan Kochanowski University, 5 \u017beromskiego Street, 25-369 Kielce, Poland"},{"name":"Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences, 36A Postepu Street, 05-552 Magdalenka, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8571-9935","authenticated-orcid":false,"given":"Lidia","family":"Wadolowska","sequence":"additional","affiliation":[{"name":"Department of Human Nutrition, Faculty of Food Science, University of Warmia and Mazury in Olsztyn, 45F Sloneczna Street, 10-718 Olsztyn, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,19]]},"reference":[{"key":"ref_1","unstructured":"National Academies of Sciences, Engineering, and Medicine, Health and Medicine Division, Food and Nutrition Board, and Callahan, E.A. 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