Understanding early prevention of obesity in children (EPOCH) interventions: Opening up the ‘black box’

Early obesity prevention interventions are complex and differ in effectiveness.  A new study unpacked the four EPOCH trials and identified key lessons for effective early obesity prevention interventions.


The Early Prevention of Obesity in CHildren (EPOCH) Collaboration includes four landmark randomised controlled trials targeting very early childhood obesity prevention in Australia and New Zealand.  A prospective meta-analysis of individual participant data across the four trials demonstrated that parent-focused interventions from early life were moderately effective in reducing BMI-z score at 18-24 months of age.  This study was published in Pediatric Obesity earlier in 2020 and can be accessed here.     


While all interventions had similar aims to prevent childhood obesity, they varied widely in the number of target behaviours (10-14), intervention features (delivery mode, setting, dose and tailoring) and the type of behaviour change techniques used. A team of EPOCH early and mid-career researchers led a study to deconstruct these interventions to understand the best ways they can be implemented at scale.  This study has been published in Pediatric Obesity with further details here.


The most commonly targeted behaviours across all interventions were diet (solid foods introduction, amounts or frequency of feeding, limiting discretionary foods and drinks), physical activity (increasing tummy time or active play, limiting television or screen time), and parents' responses to infants'  hunger and satiety cues. 


Interventions were primarily delivered face to face, in a group or individual home visits or a combination by trained health professionals, over a total of 2 to 12 sessions across trials.  Individual delivery allowed for more personalisation of the content than group delivery. 


The most commonly used behaviour change techniques across all interventions related to goal setting, social support, shaping knowledge, role modelling and persuasion by a credible source.  Examples of how these techniques were applied in the interventions are detailed in the manuscript


Interviews with principal investigators and intervention facilitators from each of the trials highlighted the importance of collaboration between researchers, policymakers and health service practitioners and the need to consider implementation and scalability issues throughout the study process.


Other key learnings related to intervention delivery, evaluation and scaling up are detailed in the publication. The interviewees commented on the importance of a participant-centred approach and having the flexibility to adapt to participants'  needs (e.g. lower socioeconomic position, diverse linguistic and cultural backgrounds, metro/rural environments) while maintaining the fidelity of key messages.


This study is unique in its inclusion of unpublished intervention resources allowing for more comprehensive identification of intervention features and behaviour change techniques than if relying on published information alone. The systematic deconstruction of interventions in combination with investigators' interviews provides important insights to inform future early childhood obesity prevention initiatives that can be delivered cost-effectively at scale.


This work was also presented at the International Society of Behavioral Nutrition and Physical Activity (ISBNPA) XChange Initiative, where it was selected as one of the top abstracts in the Special Interest Group: Motivation and Behavior Change.  Lead author, Anna Lene Seidler, very eloquently summarised the results despite the 4.45 am start, and fielded questions from interested attendees which have led to potential future collaboration. For ISBNPA XChange attendees, the presentation is available on the ISBNPA XChange web app: https://whova.com/portal/webapp/iiamn_202006/Agenda/1012922 


The study team continues to quantitatively explore how these complex interventions work, for whom, and under what circumstances.  A global trials registry has been established through the EPOCH and TOPCHILD collaborations.  For more information, visit www.topchildcollaboration.org.


For further details, please contact the team at topchild@ctc.usyd.edu.au.