Dietary habits established in childhood, often persist into adulthood highlighting the importance of early intervention. However, limited interventions exist promoting “how” to establish healthful eating behaviors in children. To create impactful interventions, it is important they are based on evidence and co-designed with end-users. Fifteen child health nurses participated in this co-design study, underpinned by the Knowledge to Action Framework. Child health nurses reviewed evidence-based statements and then workshopped practical strategies. Findings from the co-design sessions were used to inform the development of a preventive intervention. The study has important health marketing implications for conducting co-design with child health nurses.