During the past few decades there has been a gradual abandoning of the traditional Mediterranean diet by the population of Crete and especially among the younger generations. Since this is related to the rapidly increasing morbidity and mortality rates from chronic diseases, the need for educating young people on the principles of good nutrition becomes increasingly important. It is also acknowledged that the epidemiological field needs to focus on studying the implementation process, since this will allow for a deeper understanding of the outcomes.

The aims of the present study were to explore the process of implementing an innovation in Cretan primary schools and to identify best teaching practices and principles.

In three state primary schools on the island of Crete, 107 children took part in a 30-h nutrition and media education programme. Classroom observations were used to define attitudes towards the programme and teaching methods. Besides baseline and post evaluation, the pupils were also interviewed about 11 months after the end of the programme.

During observation of the teaching process, emerging issues were the teacher's motivation and interest in the course, his/her preparation before each class, teaching ability and communication skills, the respect and discipline he/she kept and the innovative teaching methods used. In some cases researcher intervention in the classroom could not be avoided.

Overall, individual teacher willingness and teaching skills were mainly responsible for the quality of teaching, the variety of educational methods used in classrooms and pupils' interest in the course. Changes in pupils' knowledge and recall of the course were related to teacher enthusiasm but also to researcher intervention. Exploring the teaching and learning process allowed a deeper understanding of the data. It is concluded that attempts to introduce the principles of a Mediterranean diet to children through nutrition education require innovative, enthusiastic and highly motivated teachers.