The objective of this article is to describe the characteristics of food consumption and eating behavior of adolescents and its association with socio-demographic factors. In 2009, a random sample of students in 9th grade of elementary education at public and private schools from 26 Brazilian state capitals and Federal District was studied. It was applied a self-administered questionnaire with socio-demographic attributes, food consumption and eating behavior, among others. Estimates of the constructed indicators were presented for the total population and by sex. The association of each indicator with socio-demographic variables was examined by logistic regression. The results showed that over half of adolescents presented frequent consumption of beans (62.6%), milk (53.6%) and sweets (50.9%), and held at least lunch or dinner with the mother or responsible (62.6%) and watching television or studying (50.9%). In general, girls were more exposed to undesirable eating habits and higher socioeconomic status was associated with a higher prevalence of the indicators studied. The results revealed regular consumption of unhealthy diet markers and consumption of less than the recommended for a healthy diet, pointing the need for strengthening health promotion activities targeting young people.