Child consumer-centered co-creation for the development of healthy dairy products: Comparative insights from diabetic and non-diabetic children.

Co-creation has gained relevance as a participatory strategy in food innovation; however, important gaps remain in child-centered applications. First, there is limited evidence on how co-creation processes perform when involving children from different health and dietary contexts, such as those with and without type 1 Diabetes mellitus (DM1). Second, studies integrating visual projective techniques such as Free Drawing into the co-creation process to systematically capture children's implicit perceptions and habitual food consumption are lacking. Third, it remains unclear whether children's participation in co-creation biases sensory acceptance when compared with evaluations conducted by non-participating peers. This study addresses these gaps by proposing and testing a child-centered co-creation framework that explicitly integrates the Free Drawing technique into the exploratory phase of product development. The framework was applied to the development of healthy dairy products enriched with fruits, vegetables, grains, and nuts, involving children with and without DM1. Forty-two Brazilian children (21 with DM1 and 21 without) participated in four co-creation phases (exploration, prototyping, refinement, and validation), while an additional 42 children (21 with DM1 and 21 without) participated exclusively in the validation stage. The Free Drawing technique revealed distinct cognitive representations between groups. Children with DM1 primarily illustrated simpler, sugar-free, or plain dairy products, whereas non-diabetic children depicted a broader range of flavored and processed options, emphasizing sweetness and indulgence. During the co-creation process, ingredient selection for the prototypes reflected four main drivers across groups: familiarity, sensory and hedonic properties, perceived healthiness, and novelty. Children with DM1 adopted a more reflective decision-making approach, incorporating a greater diversity of fruits, assigning imaginative names to their products, and prioritizing familiarity, healthiness, and sensory balance. In contrast, non-diabetic children focused more strongly on sweetness, novelty, and hedonic appeal. The refined prototypes (n = 6 per group) achieved high sensory acceptance, with no significant differences between evaluations conducted by co-creators and non-participant children, indicating that participation in co-creation did not bias sensory outcomes. Overall, this study provides the first comparative evidence that child-centered co-creation is effective across different health contexts and demonstrates that integrating Free Drawing into the co-creation process is a novel and robust methodological strategy for eliciting meaningful insights. Finally, co-creation helps to develop nutritious, low- or no-sugar dairy products aligned with children's sensory expectations.