Family-based intervention programs are insufficient to prevent childhood obesity, major study finds
Study of 17 international trials finds early childhood obesity programs targeting parents alone don’t improve BMI, prompting calls for stronger government action on environmental and structural drivers.
University of Sydney
A landmark study led by the University of Sydney has found no evidence that family-based early obesity prevention programs, such as home visits from health professionals or community parent groups, improve overall body mass index (BMI) in young children.
Published in The Lancet, the study was led by Dr Kylie Hunter from the Faculty of Medicine and Health as part of the TOPCHILD collaboration with multiple scientists including those at the University Medical Center Rostock and Flinders University.
Early weight is a strong predictor of future weight trajectory, with one in four children in Australia living with overweight or obesity by the time they start school.
"We found that early parent-focused obesity prevention programs did not improve BMI in children,” said Dr Kylie Hunter, lead author and research fellow at the NHMRC Clinical Trials Centre and the Charles Perkins Centre.
“To shift the dial, we need to stop putting the onus on families alone. Governments, health officials and local authorities must show stronger leadership and commitment to addressing the social and environmental drivers of obesity.”
Assessing the impact of childhood obesity prevention programs
The scientists analysed data from 31 international studies evaluating different types of family-based childhood obesity prevention programs commencing during pregnancy up to the age of one.
Of these 31 international studies, the researchers focused on 17 studies, which assessed children’s BMI at the age of two, after the obesity programs had concluded.
The academics found that despite the range of interventions employed there was no meaningful difference in the BMI of children in families who participated in any of the programs compared to those who did not.
The interventions analysed in the study aimed to help parents build healthy habits for their children, focusing on diet, breast-feeding, physical activity, sleep and screen time. They were delivered in a variety of ways including home visits from health professionals and peer educators, community parent groups or via mobile apps.
Recognising the limits of family-based health interventions
With a third of children and adolescents worldwide forecast to live with overweight or obesity within the next 25 years, researchers say programs are being undermined by societal factors beyond families’ control, especially those in lower socioeconomic groups.
Dr Hunter said: “It’s hard to make healthy choices when unhealthy options are cheaper, easier, and more heavily advertised. We must address the broader environments where children eat, learn and play – making healthy choices easier for everyone, regardless of where they live."
The programs analysed in the study were conducted in countries such as Australia, the UK, Norway, Belarus, Brazil, the US and Sweden and lasted from two days to 39 months.
Structural change key to obesity prevention
The researchers emphasised that the programs studied were well-designed and delivered by passionate and skilled professionals, but argued that without wider systemic change, both health professionals and parents were fighting a losing battle.
“The first phase of life is challenging for many families”, said co-author Professor Anna Lene Seidler from the German Center for Child and Adolescent Health at the University Medical Center Rostock in Germany and affiliate at the University of Sydney.
“Parents may feel overwhelmed and lack the time, resources and stability to implement healthy behaviours without broader structural support.”
The researchers warn that focusing solely on parents to make changes may also widen health inequalities.
“Families most affected by childhood obesity – often those in lower socioeconomic groups – are also the least likely to access or benefit from these programs, while families in higher socioeconomic areas, who already meet many health recommendations, are more likely to be reached,” said Dr Hunter.
About the TOPCHILD Collaboration
The TOPCHILD Collaboration is a global initiative that unites more than 70 researchers from 47 institutions, contributing original data to create the largest early childhood obesity prevention database to date, encompassing nearly 30,000 children.
-ENDS-
Journal
The Lancet
Method of Research
Meta-analysis
Subject of Research
People
Article Title
Parent-focused behavioural interventions for the prevention of early childhood obesity: results of the TOPCHILD systematic review and individual participant data meta-analysis
Article Publication Date
10-Sep-2025
The Lancet: Parent-focused programs insufficient to prevent obesity in toddlers, finds meta-analysis; authors call for a re-think of childhood obesity prevention approaches
- A meta-analysis of 17 trials including over 9,000 toddlers found no evidence that parent-focused early childhood obesity prevention programs have an impact on young children's BMI.
- Authors say their findings underscore the need to re-think current behavioural approaches to prevent obesity in early childhood and stress the need for broader, coordinated and resourced public health action.
Existing approaches to parent-focused behavioural programs delivered up to 12 months of age which aim to combat childhood obesity are insufficient to improve body mass index (BMI) at approximately two years of age, according to the largest study to date on the topic published in The Lancet.
Globally, around 37 million children under five years live with overweight or obesity [1]. Child obesity has major lifelong health impacts. To prevent obesity, many argue it is crucial to intervene early, before overweight or obesity first develop in early childhood. The WHO recommends a life-long approach to reduce the risk of obesity, starting during pregnancy. It advocates for the provision of guidance on healthy diet, sleep and physical activity in early childhood for parents/caregivers [2].
Therefore, many governments have made early parent-focused programs – such as community parenting classes, home visits or sharing information via SMS/email/app with a focus on building parent’s skills and knowledge on topics such as nutrition, physical activity, and sleep - a key strategy for obesity prevention.
However, there has been limited evidence on the effectiveness of such programs, putting policymakers in a challenging position and resulting in decisions to implement potentially resource-intensive programs despite gaps in the evidence.
Lead author Dr Kylie Hunter, University of Sydney (Australia), says, “Obesity is in large part driven by environmental and socio-economic factors that individuals are unable to change. Parents play a vital role, but our study highlights that they cannot be expected to reduce childhood obesity levels alone.
“Broader, coordinated action across society is needed to make healthy choices easier for everyone, regardless of where they live. Alongside support for parents, we need to see coordinated policies which improve affordability of healthy foods, increase access to green spaces, and regulate unhealthy food marketing to tackle childhood obesity."
The authors formed a global collaboration (TOPCHILD) of more than 70 researchers across 47 institutions, combining data from 31 trials set across 10 countries. Investigators from all trials worked together and shared their individual participant data resulting in a large dataset of 28,825 participants to examine the impact of obesity prevention programs designed to help parents foster healthy nutrition, sleep and activity patterns in their toddlers. To be included in the meta-analysis, programs needed to commence sometime between pregnancy and 12 months of age and to measure a child weight-related outcome. The authors also disentangled detailed information on the content and delivery of interventions in a complementary piece of research led by Flinders University [3].
Of the 31 trials contributing data, there were 17 trials with individual participant data which assessed BMI at approximately two years of age (a total of 9128 participants). These trialled different intervention approaches [3], including for example:
- A trial in the UK assessing a program where eight weekly sessions were delivered in children centres to groups of eight to ten parents to target behaviours including food provision and movement. [4]
- An Australian trial where women with their first child received eight home visits spread over two years with advice on topics including breastfeeding, timing of introducing solids, screen time and physical activity. [5]
- A trial in the US where primary-care providers set dietary, physical activity or screen time goals with parents, aided by low-literacy booklets, at seven visits from two to 18 months. [6]
With a high level of certainty, the meta-analysis found that the early childhood obesity prevention programs had no effect on BMI of the children at approximately two years old.
Senior author Prof Anna Lene Seidler, University of Rostock (Germany), says, “There are several potential explanations for why current parent-focused programs to prevent obesity in toddlers are not effective. One reason could be that the first year of a child’s life can be overwhelming and stressful for parents, leaving them with limited capacity to fully engage in behavioural changes. Once children enter broader social settings such as early childcare and school, programs which create healthier environments for children directly in these setting may be more effective.
“Additionally, the families most affected by childhood obesity – often those in lower socioeconomic groups – are also the least likely to be reached by parent-focused early programs. They often simply do not have the resources or time to attend and adhere to these programs, particularly in the current cost of living crisis. Policy level changes aimed at creating healthier environments for all children are more likely to reach these families.”
The authors acknowledge some limitations in their study, including that seven of the 17 trials were rated as high risk of bias due to missing data and/or that data were missing at different rates for participants in the intervention group compared to those in the control group. However, when these studies were excluded from the analysis, the results remained the same.
NOTES TO EDITORS
This study was funded by the Australian National Health and Medical Research Council. For a full list of researchers and institutions see the paper.
Quotes from Authors cannot be found in the text of the Article but have been supplied for the press release. The Comment quote is taken directly from the linked Comment.
The labels have been added to this press release as part of a project run by the Academy of Medical Sciences seeking to improve the communication of evidence. For more information, please see: http://www.sciencemediacentre.org/wp-content/uploads/2018/01/AMS-press-release-labelling-system-GUIDANCE.pdf If you have any questions or feedback, please contact The Lancet press office pressoffice@lancet.com
References:
[1] https://data.unicef.org/resources/jme-report-2023/?utm_id=JME-2023
[2] https://www.who.int/publications/i/item/9789241510066
[3] Johnson BJ, Chadwick PM, Pryde S, Seidler AL, Hunter KE et al. Behavioural components and delivery features of early childhood obesity prevention interventions: intervention coding of studies in the TOPCHILD Collaboration systematic review. IJBNPA. 2025;22:14.
[4] Bryant M, Collinson M, Burton W, et al. Cluster randomised controlled feasibility study of HENRY: a community-based intervention aimed at reducing obesity rates in preschool children. Pilot and Feasibility Studies 2021; 7(1): 59.
[5] Wen LM, Baur LA, Simpson JM, Rissel C, Wardle K, Flood VM. Effectiveness of home-based early intervention on children’s BMI at age 2: randomised controlled trial. BMJ 2012; 344:e3732.
[6] Sanders LM, Perrin EM, Yin HS, et al. A health-literacy intervention for early childhood obesity prevention: a cluster-randomized controlled trial. Pediatrics 2021; 147(5).
Journal
The Lancet Diabetes & Endocrinology
Method of Research
Meta-analysis
Subject of Research
People
Article Title
Parent-focused behavioural interventions for the prevention of early childhood obesity (TOPCHILD): a systematic review and individual participant data metaanalysis
Article Publication Date
10-Sep-2025
COI Statement
KEH declares support for the current study as an investigator from the Australian National Health and Medical Research Council (NHMRC; GNT1186363 and GNT2006999) and had travel supported by the EPOCH-Translate Centre of Research Excellence (CRE; 2023 and 2024). RKG declares support for the current study as an investigator from the NHMRC (GNT1186363, GNT2006999, and GNT1101675, and for BJJ salary support). LAB and LMW declare grant funding from the NHMRC (393112 and 1003780) and the NHMRC CRE (1101675 and 2006999). JXS is supported by an NHMRC Postgraduate Research Scholarship. LW declares salary support from the NHMRC Investigator Grant Scheme. RWT declares salary support from the Karitane Products Society. PJG is supported by the UK Medical Research Council (MC_UU_00004/06). LMS declares funding for their included trial Greenlight from the Patient-Centered Outcomes Research Institute (PCORI). KPR declares support from the NHMRC (investigator grant 2025-2029). VB declares support for the current study as an investigator from the NHMRC (GNT2006999). AJH declares payments to their institution from the NHMRC (GNT1186363). KDH declares grant funding from the NHMRC (GNT425801 and GNT1008879), and Future Leader Fellowship funding from the Heart Foundation Australia (105929). LA declares support for the current study as an investigator from the NHMRC (GNT1186363 and GNT2006999). MB declares salary support as the Principal Investigator of their included trial HENRY from the National Institute for Health and Care Research (NIHR) and has a role as member of the Board of Trustees, UK Association for the Study of Obesity (Chair 2019–22). AGF declares grants or contracts from the US National Institutes of Health (NIH), PCORI, and Agency for Healthcare Research and Quality (AHRQ); received consulting fees from the University of California, Los Angeles (UCLA), Rutgers, PCORI, and Duke University; was paid for presentations by Emory University; had travel supported by the NIH and PCORI; participated on the Data and Safety Monitoring Board for NIH trials; has a role in the American Academy of Pediatrics; and declares funding for their included trial from University Research Council faculty grant at the University of Cincinnati. KKO declares programme funding from the UK Medical Research Council (MC_UU_00006/2) and has a role as Chair of the Maternal and Child Nutrition Subgroup of the UK Scientific Advisory Committee on Nutrition. LK declares support from the Behavioural Science Institute, Radboud University. JKL declares salary and included trial support from Fonds NutsOhra (100.939). AML declares funding for their included trial from the NIH (UL1TR000117 and UL1TR001998). EO declares they are the recipient of a grant from the NIH. MJM declares support for their included trail from the US Department of Agriculture (USDA) National Institute of Food and Agriculture (2011-68001-30207 and 2017-68001-26350). IMP declares that payment to support their time was received from National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK; R01DK088244) and received consulting fees from Danone North America. EAR declares they are the recipient of a grant from the NIH and is President of the Southern Nursing Research Society. RLR declares funding for their included trials Greenlight from the NIH and Greenlight Plus from the PCORI and has received grants or contracts from the AHRQ, PCORI, NIH, US Centers for Disease Control and Prevention (CDC), and Cardiohealth Alliance. TMR declares funding for their included trial THRIVE from NIDDK(T32 DK063929) and declares they have received grants or contracts from the NIDDK (R01DK135497), Cincinnati Children’s Hospital Medical Center. HMW declares funding for their included trial Mothers and Others from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD; R01HD073237) and declares their time was funded by the NIDDK (K01DK111793). ALT declares funding for their included trial Mothers and Others from the NICHD (R01HD073237). HX declares support for the trial Healthy Beginnings involvement was provided by Sydney Local Health District (SLHD). KJJ declares salary support as the Principal Investigator of their included trial from the NIH. KdlH declares funding for their involvement from the NICHD (1R01HD092483). BC declares funding for their included trial HENRY III from the NIHR (NIHR135081). RSG declares support and has received funding from the NIH and USDA. JB declares funding and travel support from the Hawaii Community Foundation, USDA, and Kellog Foundation, received payments for presentations through various organisations. ALS declares support for the current study as an investigator from the NHMRC (GNT1186363, GNT1101675, GNT2006999, and GNT2009432). All other authors declare no competing interests.
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