Objective: To gain insight into the extent of body mass index (BMI) change during an academic year for children with overweight or obesity at entry to an early learning programme with nutrition and physical activity components ("Head Start"). We explored whether meeting with families to discuss weight and nutrition and age of entry in the programme were associated with movement towards healthy weight via a reduction in BMI. Design: Quantitative analyses of administrative Head Start data of children aged 3-5 years old who entered the programme with a BMI labelled as overweight or obese. Setting: Children who participated in a Head Start early learning programme in the Southwest USA. Method: Descriptive analyses of BMI changes over the Head Start programme year. Ordinary least square regression analyses were run to explore whether a meeting with a family regarding their child's weight and nutrition (i.e. a family service event) and age of entry predicted BMI change over the programme year. Results: Children with BMI labelled as overweight or obese, on average, reduced BMI over the academic year. Unexpectedly, having a family service event was related to an increase in BMI over the school year. Earlier age of entry predicted reduced BMI over the programme year. Conclusion: "Head Start" programming appears well suited to support decreases in prevalence of childhood obesity and that earlier entry was better. A meeting with families regarding their child's weight and nutrition predicted an increase in BMI, though several factors indicated the need for more nuanced research on the types and intensity of these events.