AbstractThis study aimed to evaluate the association between socio-economic factors and the food consumption of a young population. Participants were from the Portuguese National Food, Nutrition and Physical Activity Survey (IAN-AF 2015–2016) aged from 3 to 17 years (n 1153). Food consumption was assessed using two non-consecutive days of food diaries in children and two 24-h recalls for adolescents. A latent class analysis (LCA) was used to classify children’s socio-economic status (socio-economic composite classification (SCC)), categorised in low, middle or high. The associations between socio-economic variables and food consumption were evaluated through linear or logistic regression models, weighted for the Portuguese population distribution. A positive association was found between belonging to a higher level of SCC and consumption of fruits and vegetables (FV), by children (β = 2·4, 95 % CI 1·1, 3·8) and by adolescents (β = 52·4, 95 % CI 9·6, 95·3). A higher SCC, but particularly higher maternal education, was positively associated with consumption of ‘white meat, fish and eggs’. Both higher SCC and parental education were positively associated with salty snack consumption in the adolescents’ group. In conclusion, children and adolescents with higher educated parents and belonging to a high socio-economic level have a higher daily intake of FV and white meat, fish and eggs. Socio-economic factors play an important role in justifying differences in the food consumption of children and adolescents and must be considered in future interventions. The relationship between higher socio-economic position and salty snack consumption in adolescents needs to be further explored in other populations.