This study evaluates the perceptions of teachers in charge of coordinating health education in schools: the School Health Coordinators (SHCs). It addresses the success and barriers of the development and implementation regarding the first year of healthy eating programmes in their schools. This research is based on 16 face-to-face semi-structured interviews with SHCs from Portuguese public schools offering from fifth to ninth grades. A thematic analysis was performed and themes were identified, taking into consideration similarities and differences among the participants' opinions. The results showed that the schools in this study often involved a set of separate healthy diet promotion activities with a low level of joint effort from all members of the school. Nevertheless, in Portugal, health education is based on the broad concept that school health promotion is compulsory for all schools. Two main barriers were identified in order to explain this divergence: structural and political idiosyncrasies among schools and the food environment inside and outside the schools. The results are discussed considering the wide range of factors influencing young people's eating behaviours and recommendations are made for the different agents interacting with them in order to promote appropriate eating habits.