Do the effects of interventions aimed at the prevention of childhood obesity reduce inequities?

Prof. Carolyn Summerbell's research paper that was published recently Do the effects of interventions aimed at the prevention of childhood obesity reduce inequities? A re- analysis of randomized trial data from two Cochrane reviews - eClinicalMedicine provides new insight into whether the effectiveness of physical activity and diet interventions that aim to prevent obesity in children differs according to eight factors associated with inequity.

The work was based on her Cochrane systematic reviews, published in 2024, of 246 randomised controlled trials, Interventions to prevent obesity in children aged 5 to 11 years old - Spiga, F - 2024 | Cochrane Library and Interventions to prevent obesity in children aged 12 to 18 years old - Spiga, F - 2024 | Cochrane Library. These reviews found that interventions promoting (only) physical activity have a small beneficial effect on BMI for people aged 5–18 years, as do interventions promoting physical activity alongside healthy eating for 5–11 year olds.

She and the research team contacted the authors of all the trials that were included in these Cochrane reviews and asked if they had collected data from participants on any of eight factors associated with inequity and, if they had, would they be willing to share these data with the research team. The eight factors were place, race/ethnicity, occupation, gender/sex, religion, education, socio-economic status, and social capital (the PROGRESS framework).

Carolyn was thrilled that authors from 81 trials, that took place between 2001 and 2020, involving 84,713 participants, had collected relevant data and were willing to collaborate. Using meta-analysis techniques the research team found no substantial differences in the effectiveness of interventions for PROGRESS factors in most scenarios. However, in the younger age group (5–11 years), the effect of interventions on standardized BMI was greater in boys.

The findings suggest that those responsible for public health can promote these beneficial interventions without major concerns about increasing inequalities but should be mindful that these interventions may work better in boys aged 5–11 years than girls.

A related paper from this work, based on 204 trials in our Cochrane reviews, found that the most effective characteristic to include in an intervention to prevent obesity in children aged 5-18 years was targeting of physical activity. This paper has recently been accepted and will be published in BMJ Public Health in the next few weeks.

What’s next? Government policy strategies to tackle childhood obesity and inequalities mainly focus on diet and food systems. Carolyn will be working with policy leads in England, and European and global agencies, to change the conversation and reframe policies to put physical activity centre stage.

If you would like to discuss the project in any more detail, please get in touch through carolyn.summerbell@durham.ac.uk

To learn more about this research or Carolyn's other work see Professor Carolyn Summerbell - Durham University