Maternal depressive symptoms negatively impact mothers’ parenting practices and children's development, but the evidence linking these symptoms to children's obesity is mixed.

We use a large sample to examine contemporaneous and lagged associations between maternal depressive symptoms and children's BMI, obesity and food consumption, controlling for background characteristics.

Data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), a longitudinal study of children from infancy through kindergarten in the USA, were collected at four waves from 2001 to 2007, when children were 9 months, 2 years, 4 years and 5½years of age, through surveys, child assessments and observations.

A sub-sample of children from the ECLS-B is used (n 6500).

Between 17 % and 19 % of mothers reported experiencing depressive symptoms; 17 % to 20 % of children were obese. Maternal depressive symptoms were associated with a small decrease in the likelihood her child was obese (0·8 percentage points) and with lower consumption of healthy foods. The duration of maternal depressive symptoms was associated with higher BMI (0·02 sd) among children whose parents lacked college degrees.

Results indicate that mothers’ depressive symptoms have small associations with children's food consumption and obesity. Among children whose parents lack college degrees, persistent maternal depressive symptoms are associated with slightly higher child BMI. Findings highlight the need to control for depression in analyses of children's weight. Interventions that consider maternal depression early may be useful in promoting healthy weight outcomes and eating habits among children.