Babío, NancyHeras Delgado, Sara de lasMiguel Etayo, Pilar dePastor Villaescusa, BelénLeis Trabazo, María RosauraGarcidueñas Fimbre, Tany E.Larruy García, AliciaNavas Carretero, SantiagoPortolés, OlgaFlores Rojas, KatherineVázquez Cobela, RocíoShyam, SangeethaMiguel Berges, María L.Martínez, J. AlfredoCodoñer Franch, PilarGil Campos, MercedesMoreno, Luis A.Salas Salvado, Jordi2026-01-232026-01-232023-10-06Babio, N., de Las Heras-Delgado, S., De Miguel-Etayo, P., Pastor-Villaescusa, B., Leis, R., Garcidueñas-Fimbres, T. E., Larruy-García, A., Navas-Carretero, S., Portoles, O., Flores-Rojas, K., Vázquez-Cobela, R., Shyam, S., Miguel-Berges, M. L., Martínez, J. A., Codoñer-Franch, P., Gil-Campos, M., Moreno, L. A., & Salas-Salvadó, J. (2023). Reproducibility and relative validity of a semi-quantitative food and beverage frequency questionnaire for Spanish children aged 3 to 11 years: the COME-Kids F&B-FQ. European journal of pediatrics, 182(12), 5577–5589. https://doi.org/10.1007/s00431-023-05220-91432-1076https://hdl.handle.net/10347/45423A reliable food and beverage frequency questionnaire (F&B-FQ) to measure dietary intakes for children across Spain is currently unavailable. Thus, we designed and assessed the reproducibility and relative validity of a new F&B-FQ in 210 Spanish children aged 3–11 years. COME-Kids F&B-FQ contained 125 items to assess the usual diet intake in the past year among children. To explore the reproducibility, caregivers answered COME-Kids F&B-FQ twice over a 15-day period (± 1 week). To evaluate the relative validity, estimates from a third COME-Kids F&B-FQ administered at 1 year of follow-up were compared with the mean estimates from 3-day dietary records (3d-DR) collected at baseline, 6 months, and after 1 year of follow-up. Reproducibility and relative validity of the COME-Kids F&B-FQ in estimating food groups and nutrients were assessed using Pearson (r) and intra-class (ICC) correlation coefficients. We used the kappa index to evaluate the agreement in repeat administrations or with the 3d-DR. We used Bland–Altman plots to identify bias across levels of intake. A total of 195 children (105 boys, 90 girls) completed the study. The reproducibility of data estimated from COME-Kids F&B-FQ was substantial with mean r and ICC being 0.65 and 0.64 for food groups and 0.63 and 0.62 for nutrients, respectively. Validation assessments comparing the FFQ and 3d-DRs showed r = 0.36 and ICC = 0.30 for food groups and r = 0.29 and ICC = 0.24 for nutrients. The mean agreement for food group reproducibility and relative validity was 86% and 65%, respectively. These estimates were 85% for reproducibility and 64% for relative validity in the case of nutrients. For reproducibility and relative validity, the overall mean kappa index was 63% and 37% for all food groups and 52% and 27% for nutrients, respectively. Bland–Altman plots showed no specific bias relating to the level of intake of nutrients and several food groups. Conclusion: COME-Kids F&B-FQ showed substantial reproducibility and acceptable relative validity to assess food and beverage intake in Spanish children aged 3 to 11 years. Most children were correctly classified in relation to the intake of food groups and nutrients, and misclassification was unlikely with reference to 3d-DReng© The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International LicenseAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/ChildrenDietary assessmentFood frequency questionnaireReproduciblyValidity3206 Ciencias de la nutriciónjournal article10.1007/s00431-023-05220-90340-6199open access