A Secondary Analysis of the Childhood Obesity Prevention Literature through a Wider Determinants of Health Lens: Implications for Research Funders, Researchers, Policymakers and Practitioners

Abstract

Background: Over the last 25 years, we have made great advances in our understanding of the complex adaptive systems which drive childhood obesity. Within this, the important role of upstream interventions which focus on the wider determinants of health (WDoH) has been acknowledged. Concurrently, the number of intervention studies aiming to prevent childhood obesity has increased exponentially. One might anticipate that our understanding of theory has been embedded into the development and implementation of interventions in real time. Methods: We tested this hypothesis by conducting secondary analysis of the interventions included in the Cochrane Review on “Interventions for Preventing Obesity in Children”, published since 1993. All 153 randomised controlled trials (RCTs) were independently coded by two authors against the WDoH model using an adaptive framework synthesis approach. We used aspects of the Action Mapping Tool from Public Health England to facilitate our coding and to visualise our findings in contrast to 226 perceived causes of obesity. Results: We found that the proportion of interventions which targeted downstream (e.g. individual and family behaviours) as opposed to upstream (e.g. infrastructure, environmental, policy) determinants has not changed over time (from 1993 to 2015), with most intervention efforts (57.9%) aiming to change individual lifestyle factors via education-based approaches. Almost half of the interventions (45%) targeted two or more levels of the WDoH. Where interventions targeted some of the wider determinants, this was often achieved via upskilling teachers to deliver educational content to children. No notable difference in design or implementation was observed between interventions targeting children of varying ages (0-5 years, 6-12 years, 13-18 years). Conclusions: This study highlights that interventions, evaluated via RCTs, have persisted to focus on downstream, individualistic determinants of obesity over the last 25 years, despite the step change in our understanding of its complex aetiology. We hope that the findings from our analysis will challenge research funders, researchers, policymakers and practitioners to reflect upon, and critique, the evidence-based paradigm in which we operate, and call for a shift in focus of new evidence which takes a WDoH lens.

Preventing childhood obesity primary schools: a realist review from UK perspective

“…The planned Cochrane update effort has identified (but not extracted) a further 162 relevant trials published between 2015 and 2018 and search for trials after 2018 is ongoing. However, the included interventions in the Cochrane review did not change substantially since its first publication in 2002 (i.e., with a downstream focus on individual behaviour change) 8 and this was confirmed in a recent secondary analysis of the Cochrane review 58 using a Wider Determinants of Health lens. The findings indicate that a) the majority of studies target individual dietary and PA behaviours, and b) the focus of childhood obesity prevention interventions has not changed over time since 1993-publication date of the oldest study included in the Cochrane review.…”

Preventing Childhood Obesity in Primary Schools: A Realist Review from UK Perspective

“…The planned Cochrane update effort has identified (but not extracted) a further 162 relevant trials published between 2015 and 2018 and the search for trials after 2018 is ongoing. However, the included interventions in the Cochrane review did not change substantially since its first publication in 2002 (i.e., with a downstream focus on individual behaviour change) [ 8 ] and this was confirmed in a recent secondary analysis of the Cochrane review [ 58 ] using a wider determinants of health lens. The findings indicate that (a) the majority of studies target individual dietary and PA behaviours, and (b) the focus of childhood obesity prevention interventions has not changed over time since 1993—the publication date of the oldest study included in the Cochrane review.…”