Overview

• The TOPCHILD collaboration combined individual participant data from 31 trials across 10 countries, totaling 28,825 participants.
• Seventeen trials with 9,128 children reported BMI near age two, and the analysis found no effect of early parent-focused interventions.
• Sensitivity checks that excluded seven high–risk-of-bias trials did not change the null result, strengthening confidence in the findings.
• Programs varied widely in design, including UK group sessions, Australian home visits, and US primary‑care goal‑setting approaches.
• Study authors say parents cannot carry prevention alone and call for policies that improve healthy food affordability, expand green space access, and curb unhealthy food marketing.