Objectives This study aimed to analyze how picture books discuss and represent children's bodies and health, as well as to uncover their underlying meanings, utilizing the concepts of knowledge, power, and discourse by the post-structuralist M. Foucault. Methods To achieve this, a discourse analysis was conducted using Foucault's techniques of discipline, surveillance, and normalization on 132 picture books selected through the search of the National Library for Children and Young Adults. Results The findings revealed that these picture books reflect the standards and norms set by our society regarding children's bodies and health. They utilize the authority and status of specialized knowledge in fields such as medicine, nutrition, psychology, and sports science to regulate children's bodies by presenting different arrangements of healthy or vulnerable bodies and establishing hierarchical knowledge to secure a standardized body position. The multiplicity of voices, including the voice of narrators, illustrations, and the voice of adult readers, intertwined with gazes between characters, exerted the power of reward and punishment, allowing child readers to self-regulate regarding their bodies and health. Moreover, the ideal characteristics of children's bodies and health were reinforced through powerful discourses structured around expectations, commands, conventions, norms, declarations, and linked to broader societal discourses such as risk and deficiency, differentiated by age and gender. Conclusions The meaning and discourse surrounding children's healthy bodies were discussed within the context of how societal discourses, including risk and deficiency discourses based on age and gender, also regulate children's bodies and health. Picture books by adopting a narrative form can become a mechanism of power that (re)produces and disseminates knowledge and discourse about children.