To quantify the change in the risk of food insecurity and maternal mental disorder (MMD) before and during the coronavirus disease 2019 (COVID-19) pandemic.

Repeated cross-sectional survey. Between 17 July and 10 September 2020, mother–child pairs who were enrolled in a population-based survey in 2017 were re-contacted by telephone for consent and to complete a telephonic COVID-19 survey. We used the Brazilian Food Insecurity Scale to assess food security and the Self Reporting Questionnaire-20 to assess MMD. McNemar’s test for paired data that also accounted for clustering was used. Logistic regression was used to assess the relationship of unemployment and receipt of government assistance with food insecurity and MMD in 2020.

Ceará, Brazil.

Five hundred and seventy-seven mother–child pairs completed the 2017 and 2020 surveys. At the time of the 2020 interview, the child cohort was 36–108 months of age.

The proportion of mothers reporting food insecurity was 15·5 % higher (95 % CI 5·9, 25·1, P value < 0·001) during the pandemic in July–August 2020 as compared with November 2017, while the prevalence of MMD was 40·2 % higher during the pandemic (95 % CI 32·6, 47·8, P value < 0·001). Loss of formal employment was associated with increased risk of food insecurity, but not with the risk of MMD.

The risk of food insecurity and MMD in Ceará increased during the COVID-19 pandemic. These findings highlight the need for policies and interventions to reduce the impact of the COVID-19 pandemic on maternal and child health, nutrition and well-being in Brazil.