The Transforming Obesity Prevention for Children (TOPCHILD) Collaboration is bringing together researchers from around the world to determine how early obesity preventions work, under what circumstances and for whom.

It is a world-first to combine innovative methodologies across three projects:

  1. An individual participant meta-analysis of all available early obesity prevention trials (currently ~ 65 trials, including ~ 52,000 participants). The primary outcome is BMI z-score at age 2 and effect differences will be explored among subgroups.
  2. Interventions will be deconstructed into their target behaviours, delivery features and behaviour change techniques. These will be coded into a dataset and merged with the complete set of individual participant data created in Part 1.
  3. Prediction models will be developed using the combined datasets. This will be the first study to apply quantitative methods to determine effective intervention components for early obesity prevention.

The results will inform tailored childhood obesity prevention interventions that are effective, efficient and scalable.




NHMRC Clinical Trials Centre, NHMRC Centre of Research Excellence in the Early Prevention of Obesity in Childhood (USyd), Flinders University, The University of Sydney, The Children’s Hospital Westmead, University of Otago, University College London, Macquarie University, Monash University, Sydney Local Health District, University of Newcastle, Duke University, NYU Grossman School of Medicine, Stanford University. For a complete list of Collaborators, please see the TOPCHILD website at

Chief Investigators:

Anna Lene Seidler, Seema Mihrshahi, Kylie Hunter, Brittany Johnson, Rebecca Golley, Lisa Askie, Lukas Staub, Rachael Taylor, Paul Chadwick



Contact email:

Funded by:

NHMRC Ideas Grant (GNT1186363)

External website:

CTC staff involved:

Steering Group:

Anna Lene Seidler (Chair), Kylie Hunter (Co-deputy chair), Angie Barba, Sol Libesman, Mason Aberoumand, Jonathan Williams, Nipun Shrestha and Jannik Aagerup (data & project management)

Advisory Group:

David Espinoza, Ian Marschner, Kristy Robledo, Lukas Staub



  1. Hunter KE, Johnson BJ, Askie L, [+others], Seidler AL on behalf of the Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration. Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity. BMJ Open 2022;12:e048166. Available at:
  2. Johnson BJ, Hunter KE, Golley RK, [+others], Seidler AL on behalf of the Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration. Unpacking the behavioural components and delivery features of early childhood obesity prevention interventions in the TOPCHILD Collaboration: a systematic review and intervention coding protocol. BMJ Open 2022;12:e048165. Available at:
  3. Seidler AL, Johnson BJ, Golley RK, Hunter KE. The Complex Quest of Preventing Obesity in Early Childhood: Describing Challenges and Solutions Through Collaboration and Innovation. Frontiers in Endocrinology. 2022;12. Available at:
  4. Seidler, A., Hunter, K., Johnson, B., Ekambareshwar, M., Taki, S., & Mauch, C. et al. Understanding, comparing and learning from the four EPOCH early childhood obesity prevention interventions: A multi‐methods study. Pediatric Obesity. 2020. Available at: