Co-production is an approach to designing, delivering, and evaluating public services through strict collaboration among professionals and the people using services with an equal and reciprocal relationship. Health promotion initiatives that include education services rarely use the co-production approach. Nevertheless, the value of co-production is widely recognized, although it is considered a normative good, and scarce and mixed evidence is available in literature. The purpose of this paper is to provide evidence supporting the hypothesis that a co-production approach, applied to an intervention for preventing obesity, can be effective and efficient. To this end, an evaluation of the processes, outputs meant as intermediate results, and behavioral and economic outcomes of a public health-promotion initiative co-produced and co-delivered with adolescents (beFood) was conducted. Mixed methods were used, including field-observations, two self-reported questionnaires, and an opportunity-cost analysis that compared beFood to traditional approaches of public health promotion. The co-production model was successfully implemented and appears to be effective-more than 5000 adolescents were reached by only 49 co-producer adolescents, who reported behavioral changes (e.g., eating better and practicing more physical activity). The cost analysis showed that the co-production approach was also efficient, producing relevant savings and potentially making available more than 3000 h of professionals' time. This research can support a re-thinking of public institutions' organization, public initiatives' design, and public servants' role.
Keywords: adolescents; co-production; evaluation; health promotion; obesity prevention; opportunity–cost; public value.