20 May 2021
An analysis of the studies in the Cochrane review ‘Interventions for Preventing Obesity in Children’, which revealed that most studies focus on changing “lifestyle” behaviours, has become the latest NIHR Alert. The analysis was by a team including researchers from the NIHR Applied Research Collaborations (ARCs) West and North East and North Cumbria.
The Cochrane review is widely used by policymakers internationally. This overwhelming focus on changing individual behaviours, such as diet and physical activity, could influence the types of policy that governments put in place to prevent childhood obesity. NIHR Alerts are short summaries of the latest health research presented in plain English, to promote the use of research by all members of society.
The team analysed the 153 randomised control trials – the best test of an intervention – that are included in the Cochrane review. They used a tool from Public Health England to categorise the types of interventions tested in each trial into:
They also looked at how the focus of the trials has changed between 1993 (the earliest trial) and 2015 (the most recent trials), and whether there was any difference in the focus of interventions for various age groups (0-5 years, 6-12 years, 13-18 years).
Over the last 30 years, research has shown that healthier environments are needed to prevent childhood obesity. Obesity is the result of many different factors that all connect to one another. Despite broad acknowledgement of this, over 90 per cent of the trials had some focus on changing individual lifestyle factors.
The researchers also found that the focus of these studies hadn’t changed much since 1993. They persisted in their focus on directly changing diet and physical activity, despite demonstrating very limited effectiveness. The focus of interventions was also consistent between those targeting children from different age groups.
Dr James Nobles, Senior Research Associate at NIHR ARC West, said:
“Fundamentally, we need to start looking at policies and interventions that affect entire populations and require less individual agency. A good example of this is the Soft Drinks Industry Levy, otherwise known as the “sugar tax”. This has the potential to change the dietary patterns of the population as a whole, with little-to-no effort required by the individual. This type of policy might be more challenging to evaluate, but it offers the potential to reduce rather than widen inequality.
“We need to try and understand more about how research informs policy in this field. Scientists need to improve the dissemination and implementation of their findings, and to understand more about the policy context so that their research can feed directly into policy agendas in a timely fashion.
“I would also like to keep pushing the need for different research designs in Public Health. We cannot be reliant on randomised controlled trials. We need alternative approaches to evaluate the complexity of what goes on in public health policy-making.”