Family-based intervention programs are insufficient to prevent child obesity, major study finds

11 Sep 2025

A landmark study has found no evidence that family-based early obesity prevention programs improve overall body mass index (BMI) in young children.

Published in The Lancet, the study was led by the University of Sydney with researchers from University College Cork (UCC), the University Medical Center Rostock and Flinders University. 

Early weight is a strong predictor of future weight trajectory, with 1 in 5 children in Ireland 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.  

“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.”

Methodology 

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 Karen Matvienko-Sikar, Senior Lecturer, School of Public Health, University College Cork said: “Our evidence suggests that without appropriate systems and structures in place, parent-focused interventions cannot and do not work as we would hope. Approaches to support healthy child growth and behaviours such as diet and exercise need to address the environments in which families live and grow.” 

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 they 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.  

“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. 

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.