MRC Epidemiology Unit

Street space reallocation measures, such as Low Traffic Neighbourhoods (LTNs), have attracted substantial controversy in the UK and elsewhere, for instance around reported poor engagement with residents and local actors. However, limited attention has been given to the political-economic context shaping scheme implementation, such as the impacts of reduced resources or the use of short-term, contingent funding. Based on 37 interviews with officers and councillors who implemented or sought to implement LTNs in 12 English local authorities, and part of a larger project investigating the impacts of LTNs in London, this paper addresses the gap. It shows how challenges to design, engagement and delivery are often linked to funding scarcity and processes of projectification, advancing the literature on transport governance and controversy. • Limited attention has been paid to the political-economic context shaping the implementation of Low Traffic Neighbourhood schemes • Existing approaches to funding active travel schemes, which in the context of austerity urbanism exacerbate the negative aspects of projectification, affect the success of schemes • Schemes require significant investment in terms of staff time and knowledge • They would also benefit from more funding to deliver greening aspects • The effects of austerity and projectification are exacerbated within uneven geographical areas • Local authorities with access to additional internal resources were able to implement and sustain schemes and learn from mistakes • Less resrouceful local authorities saw initial failures translate into increasing challenges for future schemes and an overall inability to implement successfully

Outdoor play benefits children’s mental wellbeing, social and cognitive development and physical activity levels. However, children’s outdoor play and physical activity have declined in recent years and barriers exist within their physical and social environment. Forest Schools (FS) can encourage outdoor play through familiarisation with local green spaces, but suitable spaces are limited in dense urban areas. The Play in Urban Spaces for Health (PUSH) intervention is a concept involving the use of primary school staff to support familiarisation of and regular play in local outdoor urban spaces for children aged 4–7 years. This could facilitate sustained behaviour change, whereby children use these sites with their families and have the capability and motivation to create opportunities for play within other outdoor urban spaces. The aim of this research study was to explore the prospective acceptability and feasibility of the school-led outdoor play intervention element of PUSH considering: (1) The acceptability of PUSH among primary school teaching staff and their perceived barriers and facilitators to implementation, and (2) The learning from people involved in strategic oversight and delivery of FS in urban areas, and perceived outcomes of FS. 18 semi-structured interviews were conducted in Bradford, Yorkshire and Tower Hamlets, London UK using co-created topic guides: eight with teachers and headteachers at primary schools near potential urban play spaces to explore acceptability, and barriers and facilitators to potential future implementation of PUSH; and ten with staff involved in strategic oversight or delivery of FS through primary schools (either primary school staff or staff from private FS providers who are commissioned by schools) to capture learning and outcomes from taking children to local green spaces for outdoor play. Interview audio files were transcribed verbatim and coded deductively to explore acceptability using the theoretical framework of acceptability and inductively drawing on whole systems thinking to explore feasibility. This was subsequently followed by generation and revision of feasibility themes. The findings were used alongside insight from the broader PUSH research and academic literature to subsequently develop a theory of change and logic model. PUSH was generally found to be acceptable. Anticipated outcomes of PUSH aligned with those perceived by participants involved in FS. Potential barriers to implementing PUSH included curriculum pressures and safety of public spaces. However, the learning from staff involved in delivering FS provided potential solutions to incorporate into the intervention design. This included linking outdoor play to the curriculum, implementing safety rules with children when at public sites, and ensuring parents are informed of where children are being taken and of the importance of outdoor play for academic learning. The findings informed the intervention theory of change and logic model for the purpose of identifying potential mechanisms of change and guiding future implementation and evaluation. This study offers preliminary evidence to support the delivery of the PUSH intervention within primary schools, which may support children’s habitual outdoor play. The findings emphasise the need to incorporate activities to ensure parent and staff buy-in prior to a pilot project.

BackgroundParticipatory systems mapping (PSM) methods are increasingly applied in population health research to understand and address complex challenges. Despite their growing use, there remains limited understanding of how these approaches are implemented in practice. This systematic scoping review aimed to explore the application of PSM in population health research, identify methodological gaps and highlight opportunities for advancing methods development and reporting standards, with particular attention to participatory approaches.MethodsA systematic search of OVID MEDLINE and Scopus identified peer-reviewed papers published in English between January 2000 and September 2023 that: (1) applied and presented the results of PSM related to population health or health improvement questions and (2) incorporated a participatory design. Two reviewers screened and assessed papers, extracting data on study characteristics, participatory approaches, map features and integration of conceptual frameworks and methods not directly related to PSM.ResultsIn the 123 included studies, involving stakeholders in building causal loop diagrams was the most commonly used approach. Variability was evident in geographical focus, study design, application and reporting. Participant involvement was mostly limited to map building, with less engagement in map validation. Significant gaps in reporting study samples and procedures were identified. A small number of studies involved end users or people with lived experiences in mapping processes. Only a few studies evaluated stakeholders’ experience with participatory processes. Lessons learnt on participatory processes include: PSM in population health benefits from cross-disciplinary, inclusive collaboration and capacity-building efforts that support meaningful involvement, shared ownership and trust among diverse stakeholders. Adaptability in the design of PSM approaches, continuous reflection and long-term partnerships are essential to maintaining relevance, enhancing impact and fostering systemic change over time.ConclusionsTo advance participatory systems mapping in population health, there is a need for further methodological innovation, stronger stakeholder engagement and more transparent, reflexive reporting practices. Building capacity through training, practical guidance and cross-disciplinary communities of practice will also be essential to support rigorous and inclusive application of these methods.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12961-026-01457-6.

Public health policy and practice are often described by means of a metaphor that depicts interventions as "upstream" efforts to prevent people from falling into a river, from which they must be rescued "downstream" by overwhelmed healthcare services. The upstream-downstream metaphor has been described as public health's defining metaphor. We apply a commercial determinants of health lens to re-engage with the initial intentions of McKinlay's seminal 1975 essay from which this metaphor emerged, and to critique its current uses. We examine how the upstream-downstream metaphor has come to be used in ways that depart radically from its original intent, which was to characterise the practices of powerful commercial actors who profit from the production of harm and disease. The subtle but important shift in language from people being pushed, to falling into the river, among other depoliticising processes, contributes to an individualising and victim-blaming approach to health harms, deflecting from the role of commercial power and practices. There is a pressing need to reclaim public health's defining metaphor as part of the wider agenda to address commercial determinants as the major public health challenges of our time.

To determine whether early gestational diabetes (GDM) differs from later GDM in maternal characteristics and perinatal outcomes. This is a secondary analysis of an energy-restricted dietary intervention in GDM (DiGest) randomized controlled trial. We compared maternal weight, glycemia, and pregnancy/neonatal outcomes between the early GDM (< 20 weeks, n = 118) and standard GDM diagnosis (21–28 weeks, n = 299) groups. Early GDM was associated with higher antenatal (40 vs. 38 mmol/mol; p = 0.017) and postnatal HbA1c (38 vs. 36 mmol/mol; p = 0.002) and higher risk of diabetes/prediabetes postnatally (19 vs. 6%; p = 0.003). Despite higher medication requirements, perinatal outcomes did not differ. Lower gestational weight gain (2.5 vs. 5.3 kg, p = 0.003) and comparable glycemia at 36 weeks were found. Timing of diagnosis did not impact the effect of the DiGest intervention. Early GDM reflects more severe underlying hyperglycemia, but timely treatment and reduced gestational weight gain can offset adverse perinatal risks.

Obesity impairs metabolic flexibility-the capacity to adapt to fluctuating energy demands. Emerging evidence suggests that dietary interventions, particularly time-restricted feeding (TRF), may help restore this flexibility. In this study, we demonstrate that feeding upregulates PRMT3 and asymmetric dimethylarginine (ADMA)-containing proteins via insulin-pAKT signaling, while fasting reduces their expression. Pharmacological inhibition of PRMT3 attenuates diet-induced obesity (DIO) and enhances adipocyte glycolysis in male mice. Mechanistically, PRMT3 drives the expression of citrate transporter SLC25A1 during feeding through direct arginine methylation. A 16:8 TRF regimen normalizes PRMT3 and ADMA levels while suppressing SLC25A1 expression. Notably, PRMT3 inhibition recapitulates the metabolic benefits of 16:8TRF and improves metabolic flexibility. Furthermore, adipocyte-specific deletion of Slc25a1 in male mice protects against DIO and enhances insulin sensitivity. Collectively, these findings identify PRMT3-mediated arginine methylation in vWAT as a nutrient-responsive regulatory axis that impairs metabolic flexibility in obesity, which is a potential therapeutic target.

On 1 April 2018 the South African Health Promotion Levy on sugary beverages (HPL) came into effect with the goal of lowering the consumption of sugar sweetened beverages (SSBs) across the South African population. The Republic of South Africa, following the economic and nutrition transitions that occurred after the end of Apartheid, has one of the highest rates of obesity in sub-Saharan Africa. Within this context, this qualitative study examined the food choices and food access of young people living in one neighbourhood of Khayelitsha, Cape Town in 2019 during the period soon after the implementation of the HPL. Through seven focus group discussions, we spoke with 71 young people (18-34) about their lives in Khayelitsha, their understandings and perceptions of food choices, food access, health and the HPL. Using a critical theory approach, we assessed the role of on-going income inequalities and high rates of unemployment on the lives of young, low-income South Africans, as well as how this continued to impact their food access, choices, and awareness of health. At the time of this study, the HPL was not having the desired impact in shifting and lowering the consumption of SSBs amongst this population. We used this exploration of the individual experience of the HPL in Khayelitsha as a metric for a critical policy reflection over time; adding to the small number of qualitative studies on this topic, strengthening the evidence for the inclusion of social and historical context in assessing global health interventions in local settings.

Early-life factors, including postnatal nutrition, shape long-term health outcomes with epigenetic effects being implicated but poorly understood in the process. Zinc-finger protein 57 (ZFP57), is an epigenetic regulator of genomic imprinting, a process controlling gene expression based on parental origin with a vital role in prenatal growth. Here, we report an imprinting-independent function of ZFP57 in postnatal resource control via the mammary gland. ZFP57 influences multiple mammary gland phenotypes, including ductal branching and cellular homeostasis with its absence leading to significant differential gene expression related to alveologenesis and lactogenesis and altered milk composition. Zfp57-/- dams attenuate offspring growth, with impacts on offspring metabolic health; effects exacerbated when pups are raised by a dam of a different genotype than their birth mother. The study identifies ZFP57 as a major regulator of both pre and postnatal resource control in mammals, offering new insights into early factors influencing lifelong health.

Findings from family-based analyses, such as sibling comparisons, are often reported using only odds ratios or hazard ratios. We demonstrate how this can be improved upon by applying the marginalized between-within framework.We provide an overview of sibling comparison methods and the marginalized between-within framework, which enables estimation of absolute risks and clinically relevant metrics while accounting for shared familial confounding. We illustrate the approach using Swedish registry data to examine the association between maternal smoking and infant mortality, estimating absolute quantities (e.g., cumulative risks), average treatment effects, attributable fractions, and numbers needed to harm (or treat).The marginalized between-within model decomposes effects into within- and between-family components while applying a global baseline across all families. Although it typically yields similar relative estimates to conditional logistic or stratified Cox regression, the model's specification of a baseline enables the estimation of absolute measures. In the applied example, absolute measures provided more interpretable and policy-relevant insights than relative estimates alone. Code for implementation in Stata and R is provided.The marginalized between-within framework may strengthen the interpretability of family-based analysis by enabling absolute and policy-relevant estimates for both binary and time-to-event outcomes, moving beyond the limitations of solely relying on relative effect measures.

Despite the benefits of physical activity (PA), evidence suggests around 25% of adults fail to meet PA guidelines, parents, and mothers in particular, and engage in less PA on average than their childless peers. This review sought to determine the correlates of parental PA, stratifying evidence by self-report and device-based measures. Quantitative studies (cross-sectional and longitudinal) investigating associations between correlates and parental PA (ie,parents with children aged 0-18y) were identified across 4 databases (MEDLINE, EMBASE, PsycINFO and Scopus) up to October 2024. Correlates (assessed in 3 or more studies) and direction of associations were extracted, described, and synthesized narratively according to the socioecological model (individual, interpersonal, organizational, environmental, societal). Of 4632 studies identified, 269 full texts were assessed and 105 studies included in the review. A total of 117 correlates were identified across all studies (103 for self-report measures, 55 for device-based). 53 correlates were assessed in 3/+ independent associations (n = 51 self-report, n = 14 device, n = 12 both). Consistently, partner PA was positively associated with parent PA regardless of measure used. Child PA, pet ownership, and environmental aesthetics were positively associated with (mothers') PA, whereas car ownership was negatively associated with PA. Only one policy-level factor (COVID-19 restrictions) was assessed, being negatively associated with parental PA. Family-based correlates of PA were positively associated with parental PA, suggesting these may support wider family engagement in PA. Evidence from fathers and from low- and middle-income countries is needed to gain a better understanding of parental PA in these groups.