Background Research has highlighted links between impulsivity and weight in children and adults. Nevertheless, little is known about the nature of this link in very young children or about the underlying mechanism by which impulsivity leads to greater adiposity. Objective The present study aimed to explore relationships between impulsivity, weight and eating behaviour in a sample of 95 2 to 4-year-olds. Method Parent–child dyads visited the laboratory and consumed a meal after which parents completed measures of child impulsivity, eating behaviour and parental feeding, whilst children completed impulsivity tasks measuring the impulsivity facet delay of gratification (Snack Delay task), motor impulsivity (Line Walking task) and inhibitory control (Tower task). Results Pearson's correlations showed that girls with greater motor impulsivity were heavier. Additionally, monitoring moderated the relationship between impulsivity and food approach behaviour, indicating that monitoring may protect more impulsive children from displaying problematic eating behaviours. Conclusions The motor impulsivity facet appears particularly relevant to child weight; parents can modulate the impact of impulsivity on child eating behaviour through their feeding style.