This paper analyses the production and reception roles of 7- to 9-year-old children and 13- to 15-year-old adolescents in two-party, three-party and multi-party encounters in the dietary counseling of diabetics. In the two-party encounters, the adolescents had an active patient role, even though their engagement withered if they had to go through a long examination or if they were asked about a 'delicate issue'. In the three-party encounters, despite their good interactional competence, they often turned into withdrawn bystanders when the parent spoke on their behalf, complemented or corrected their talk. The 7- to 9-year-old children were mostly silent and the mother spoke for them. However, they were ready to answer the questions that were clearly addressed to them. Furthermore, they had their own interaction patterns. Firstly, even when absorbed in their play, they sharply intervened in the adults' talk in order to correct an inaccurate detail. Secondly, they participated in the interaction in their playing. In the multi-party encounters with four or five participants, the more adult participants there were, the more marginalised role the child patient had.