Parental body image dissatisfaction (BID) is associated with children’s weight in cross-sectional studies; however, it is unknown whether BID predicts development of adiposity. The objective of the present study was to investigate the associations between maternal dissatisfaction with her or her child’s body and children’s BMI trajectories.

Longitudinal study. Maternal dissatisfaction (BID) with her and her child’s body was calculated based on ratings of Stunkard scales obtained at recruitment, as current minus desired body image. Children’s height and weight were measured at baseline and annually for a median of 2·5 years. Mixed-effects models with restricted cubic splines were used to construct sex- and weight-specific BMI-for-age curves according to maternal BID levels.

Public primary schools in Bogotá, Colombia.

Children (n 1523) aged 5–12 years and their mothers.

After multivariable adjustment, heavy boys and thin girls whose mothers desired a thinner child gained an estimated 1·7 kg/m2 more BMI (P=0·04) and 2·4 kg/m2 less BMI (P=0·004), respectively, between the age 6 and 14 years, than children of mothers without BID. Normal-weight boys whose mothers desired a thinner child’s body gained an estimated 1·8 kg/m2 less BMI than normal-weight boys of mothers without BID (P=0·02). Maternal BID with herself was positively related to children’s BMI gain during follow-up.

Maternal BID is associated with child’s BMI trajectories in a sex- and weight-specific manner.