Measuring breakfast dietary patterns in Spanish youth: Reliability of the Spanish Youth Breakfast Consumption Questionnaire (SYBC-Q).

Background: Reliable tools to assess breakfast habits are essential, as breakfast quality is linked to health and development in youth. However, validated instruments for Spanish children and adolescents are scarce. Objectives: To assess the reliability of the Spanish Youth Breakfast Consumption Questionnaire (SYBC-Q) in a sample of Spanish children and adolescents. Methods: A total of 248 young people participated in the study: 77 children (46.8% girls; 10.7 ± 0.7 years) and 171 adolescents (50.3% girls; 14.1 ± 1.7 years). They completed the questionnaire twice, 14 days apart, on the same days of the week and schedule. The tool includes 21 items grouped into seven food categories and two breakfast quality scores. Test-retest reliability was analyzed using the kappa coefficient (κ) and Spearman's correlation (Rho). Analyses were performed separately by age group and gender. Results: Children showed an acceptable to good level of agreement and a moderate to high correlation between test and retest (κ: 0.23-0.71; Rho: 0.37-0.76). However, low agreement and poor correlation were found for 'Take Cheese' and 'Take Milk dessert' in girls (both, κ < 0.20; Rho < 0.30). Adolescents presented an acceptable to perfect level of agreement and a low to high correlation between test and retest (κ: 0.24-0.82; Rho: 0.24-0.82), but a low level of agreement in the items 'Take pâte' in girls and 'Take dried fruits' in boys (both, κ: < 0.20; Rho: < 0.30). Conclusion: Overall, the SYBC-Q is a reliable tool for assessing the breakfast consumption and quality in Spanish children and adolescents.