[Salivary cortisol as a measure of stress during a nutrition education program in adolescents]

To analyse the stress level at different academic times, by measuring salivary cortisol and assessing the influence of the stress level on the effectiveness of a nutrition education program for adolescents.

Salivary cortisol of 42 compulsory secondary education students was determined (morning and evening) at the beginning of the course and in the time prior to final exams. A nutrition education program was developed during the course and food consumption data were collected by means of a food frequency questionnaire in both initial and final moments. In addition, the body mass index was determined.

The initial morning cortisol level was lower with respect to the final morning level (P < 0.05), with higher levels in females (P < 0.05). In the final determination, the morning cortisol was also higher in girls (P < 0.01). There were no significant changes in body mass index. 23.8% of students referred fewer consumption of carbonated beverages after the intervention program, while 28.57% reported having breakfast before leaving home. A reduction in the consumption of fruit at the end of the study was observed.

To properly assess whether the observed changes are related to the nutrition education program or with the stressful situation due to the proximity of the exams, which would imply an increase in the intake, more studies would be necessary at the different stages of the course.