Understanding the socio-economic inequalities in dietary intake is crucial when addressing the socio-economic gradient in obesity rates and non-communicable diseases. We aimed to systematically assess the association between socio-economic position (SEP) and dietary intake in Chile.

We searched for peer-reviewed and grey literature from inception until 31 December 2019 in PubMed, Scopus, PsycINFO, Web of Sciences and LILACS databases. Observational studies published in English and Spanish, reporting the comparison of at least one dietary factor between at least two groups of different SEP in the general Chilean population, were selected. Two researchers independently conducted data searches, screening and extraction and assessed study quality using an adaptation of the Newcastle Ottawa Quality Assessment Scale.

Twenty-one articles (from eighteen studies) were included. Study quality was considered low, medium and high for 24, 52 and 24 % of articles, respectively. Moderate-to-large associations indicated lower intake of fruit and vegetables, dairy products and fish/seafood and higher pulses consumption among adults of lower SEP. Variable evidence of association was found for energy intake and macronutrients, in both children and adults.

Our findings highlight some socio-economic inequalities in diets in Chile, evidencing an overall less healthy food consumption among the lower SEP groups. New policies to reduce these inequalities should tackle the unequal distribution of factors affecting healthy eating among the lower SEP groups. These findings also provide important insights for developing strategies to reduce dietary inequalities in Chile and other countries that have undergone similar nutritional transitions.