Factors affecting the BMI in adolescents attending the 2nd and 3rd cycles in Portuguese schools from Viseu

Introduction: Many studies show that the prevalence of overweight and obesity among children is rapidly increasing and developing into a major public health problem worldwide. Objectives: To assess the Body Mass Index (BMI) in school children from 2nd and 3rd cycles in Viseu schools and identify the sociodemographic, behavioural and educational factors that are related to the BMI. Methods: This is a quantitative descriptive and explanatory study with a convenience sample of 742 students attending schools of the 2nd and 3rd cycles in Viseu. The study was carried out by means of a questionnaire, which was produced for this study and previously submitted to the approval of the competent authority (DGE) for application in school context. Results: It was found that some sociodemographic factors were associated with BMI, namely age, school year, practicing high competition sport, being federate in a sport or vegetarian diet. Regarding the educational factors associated with BMI these included only the seminars given at school by specialist in nutrition. Furthermore, a significant relation between BMI and SF was found, where SF represents the school sources of knowledge. Finally among the behavioural factors associated to BMI stood: learning in classes, playing in the open air, reading books and use of internet. Conclusions: The results reinforce the need of adolescents to practice a healthy lifestyle and the role of family and school in providing the right information to help making right food choices. Finally in the sample at study the incidence of overweight and obesity was not at all preoccupying, thus indicating that the efforts to provide a good education both at home and at school are adequate and must be carried on