Reporting children’s food consumption: a comparison of reliability between a 2-day food record and a 7-day food diary

Abstract Background Monitoring eating behavior of children is critical to understanding risks for developing nutrition-related diseases in later life. While accurately assessing children’s food intake is important, collecting reliable data about children’s food intake remains challenging. Limited validated tools exist, and issues of dietary intake assessment such as recall accurateness, portion size estimation, and participant burden persist. In a previous study conducted in Switzerland, a 7-day food diary assessing eating behavior of school-aged children was developed and tested for reliability, showing high levels of agreement between parents and children. In this study, a shorter, 2-day food consumption record was developed and tested. The objective of this study was to compare the reliability of the two instruments, measuring the level of agreement between children and their parents when reporting a child’s food consumption. Methods A cross-sectional study was conducted in Switzerland (April–June 2014) among 589 children and one of their parents, where 299 completed a 7-day diary and 290 completed a 2-day tick box record. Children and parents independently reported what the child ate at six eating occasions. To assess agreement, Cohen’s Kappa, Kendall’s tau-b and Spearman’s non-parametric correlations were used. Lin’s concordance correlation coefficient and corresponding 95% confidence interval was also computed. Results With the 2-day food record, Kendall’s tau-b correlations ranged from 0.66 (whole grains) to 0.85 (proteins). Kappa values showed moderate to substantial agreement for all food categories, ranging from 0.47 for dairy products to 0.75 for fat meat and fast food. Agreement between child’s and parent’s reporting was similar for both genders. Large Kendall’s tau-b and Spearman’s correlations were found for almost all foods in all school grades. Conclusions The 2-day tick box food record showed a higher level of agreement between parents and children of all ages (7–14) and for both genders as compared to the 7-day food diary. Moreover, the 2-day food record tool simplifies data collection and data entry procedures, while providing reliable data about children’s food intake. Thus, this instrument could be used to reliably collect food intake directly from children without parental involvement.