Health behaviours as predictors of the Mediterranean Diet adherence: a decision tree approach

Objective This study aimed to identify health behaviours that determine adolescent's adherence to the Mediterranean Diet through a decision tree statistical approach. Design Cross-sectional study, with data collected through a self-fulfilment questionnaire with five sections: 1) eating habits; 2) adherence to the Mediterranean Diet (KIDMED Index); 3) physical activity; 4) health habits; 5) sociodemographic characteristics. Anthropometric and blood pressure data were collected by a trained research team. The Automatic Chi-square Interaction Detection (CHAID) method was used to identify health behaviours that contribute to a better adherence to the Mediterranean Diet. Setting Eight public secondary schools, in Algarve, Portugal. Participants Adolescents with ages between 15 and 19 years old (n 325). Results According to the KIDMED Index, we found a low adherence to MD in 9.0% of the participants, an intermediate adherence in 45.5% and a high adherence in 45.5%. Participants that regularly have breakfast, eat vegetable soup, have a second piece of fruit per day, eat fresh or cooked vegetables one or more times a day, eat oleaginous fruits at least 2 to 3 times a week, and practice sports and leisure physical activities outside school show higher adherence to the MD (P Conclusions The daily intake of two pieces of fruit and vegetables proved to be a determinant health behaviour for high adherence to MD. Strategies to promote the intake of these foods among adolescents must be developed and implemented.