Maternal Misperception of Child Body Size and Its Association with Information-Seeking Opportunities and Information Sources in Japanese Preschool Children

<b>Background/Objectives</b>: This study examined associations between maternal misperception and information-seeking opportunities, behaviors, and sources among Japanese mothers of preschool children. <b>Methods</b>: A cross-sectional online survey was conducted among mothers registered with a nationwide research panel. Mothers of children aged 3-5 years were included because, in Japan, this period follows the last early-childhood health checkup at age 3, after which caregivers are required to monitor child growth independently. In total, 1358 mothers were analyzed. Child anthropometric data were reported by mothers with reference to the Maternal and Child Health Handbook or childcare records. These measurements were originally obtained during routine health checkups conducted by healthcare professionals or childcare staff. Body mass index z-scores were categorized as high, middle, or low, and maternal perception as accurate, overestimated, or underestimated. Information-seeking behaviors were assessed using study-specific items informed by prior literature and reviewed by experts to ensure content and face validity. Health literacy was measured using the validated 12-item Japanese Health Literacy Scale, which has demonstrated reliability and validity in previous studies. Multinomial logistic regression was used. <b>Results</b>: Among children with high body size, 150/188 (80.8%) of mothers underestimated body size; among those with low body size, 20/35 (57.1%) overestimated it. In multivariable analyses, use of healthcare providers as an information source was statistically associated with maternal overestimation of child body size. <b>Conclusions</b>: Maternal misperception was common across body size categories. Further research is needed to determine whether support in interpreting objective growth indicators is associated with improved perception accuracy.