To describe the time trends and socio-economic inequalities in infant and young child feeding practices in accordance with the Brazilian deprivation index (BDI).

This time-series study analysed the prevalence of multiple breast-feeding and complementary feeding indicators based on data from the Brazilian Food and Nutrition Surveillance System, 2008–2019. Prais–Winsten regression models were used to analyse time trends. Annual percent change (APC) and 95 % CI were calculated.

Primary health care services, Brazil.

Totally, 911 735 Brazilian children under 2 years old.

Breast-feeding and complementary feeding practices differed between the extreme BDI quintiles. Overall, the results were more favourable in the municipalities with less deprivation (Q1). Improvements in some complementary feeding indicators were observed over time and evidenced such disparities: minimum dietary diversity (Q1: Δ 47·8–52·2 %, APC + 1·44, P = 0·006), minimum acceptable diet (Q1: Δ 34·5–40·5 %, APC + 5·17, P = 0·004) and consumption of meat and/or eggs (Q1: Δ 59·7–80·3 %, APC + 6·26, P < 0·001; and Q5: Δ 65·7–70·7 %, APC + 2·20, P = 0·041). Stable trends in exclusive breast-feeding and decreasing trends in the consumption of sweetened drinks and ultra-processed foods were also observed regardless the level of the deprivation.

Improvements in some complementary food indicators were observed over time. However, the improvements were not equally distributed among the BDI quintiles, with children from the municipalities with less deprivation benefiting the most.