Objective: To analyse the dietary intake of Brazilian adolescents and investigate its association with sociodemographic factors as well as health-risk and health-protective behaviours.
Design: Cross-sectional study.
Setting: The study was based on data supplied by the National Survey of Schoolchildren's Health (2012) on sociodemographic factors, dietary intake and health-risk and health-protective behaviours of schoolchildren in Brazil. A nutritional scale was elaborated combining markers of healthy and unhealthy diets. Poisson regression analysis was applied to investigate the association between the sociodemographic factors and regular intake (≥5 times/week) of selected foods; linear regression analysis was applied to investigate the association of sociodemographic and behavioural factors with nutritional scale score.
Subjects: A total of 109 104 adolescents attending the ninth year of education at 2842 schools in Brazil.
Results: Fewer than 30 % of the adolescents consumed raw or cooked vegetables on a regular basis, whereas more than one-third reported regular intake of sweets, soft drinks and sweet biscuits. Adolescents from the southern area and the oldest ones were those most exposed to inadequate dietary intake. The nutritional scale average score was higher in the students attending public school and exhibited a positive correlation with protective behaviours, such as being physically active, having meals with parents and eating breakfast, and a negative correlation with risk behaviours such as eating while studying or watching television and having smoked, drunk alcohol or used other drugs in the previous 30 d.
Conclusions: The results indicate an association between undesirable nutritional habits and other risk behaviours among Brazilian adolescents.
Keywords: Risk factors.