Child watching television

Unhealthy food advertising to children: Impacting on a watershed policy

Obesity affects a third of UK children and is a major determinant of health inequality and outcomes with substantial cost implications. University of Liverpool research showed that a 9pm watershed on unhealthy food advertising on television would reduce childhood obesity, improve health outcomes and deliver substantial health cost benefits. This has led to the adoption of a major new and unique UK-wide public health policy to introduce a watershed on advertising as part of their obesity strategy.

The challenge

Nearly a third of children in the UK are living with overweight or obesity, which can have negative impacts on their lifelong health. Exposure to unhealthy food advertising via TV or the internet had been implicated in the development of unhealthy diets and weight gain in children. Evidence of this impact on eating and weight in children, along with viable options for an effective policy for the UK around advertising to children was needed to take action on this serious issue.   

Our research

Liverpool’s Appetite and Obesity research group were the first to synthesise (using systematic review and meta-analysis) existing studies that measured the effect of exposure to unhealthy food advertising on children. They found that food advertising exposure caused greater food intake. The team also evaluated the effectiveness of the government’s existing policy on food advertising by conducting monitoring studies of food advertising patterns on the UK television channels most popular with children. Findings demonstrated that the policy had not meaningfully reduced children’s exposure to unhealthy food advertising since its inception in 2007. The team then modelled the impact of an alternative policy option (a 9pm watershed) and showed that it had the potential to substantially reduce overweight and obesity in children, particularly in those from more deprived households, therefore promoting better health and reduce inequality.

Working in partnership

Through collaboration with the Obesity Health Alliance (a coalition of over 45 health charities, medical royal colleges and campaign groups), the team showed that the majority of food and drink adverts shown during family viewing time would be banned from children’s TV under the 2007 Ofcom rules. This work highlighted one key weakness of the current regulations, that to determine which programming the rules apply to, the 2007 rules use proportion of children in the viewing audience, not the number. Therefore programmes such as primetime entertainment shows that are watched by the largest number of children were exempt from the rules because they also have a large adult viewing audience.

Outputs and outcomes

The team recommended that a 9pm watershed for unhealthy food and beverage advertising on television in the UK would prevent unhealthy food advertising being broadcast during family viewing time – and therefore would be a more effective policy for reducing children's exposure than the 2007 rules.

In July 2020, the UK Government announced a new obesity strategy including a 9pm watershed for high in fat, salt and sugar food advertising on television. The Department of Health and Social Care corroborated the key role of Professor Boyland’s research and knowledge translation in the decision-making underpinning the introduction of the health policy, greater restrictions on unhealthy food advertising in the UK.


Our research in psychology at the University of Liverpool has made a unique and material contribution to evidence-based policy making in the UK, and it is a source of pride that we have been able to inform a policy that will better protect children and young people from the harmful effects of unhealthy food advertising on television.

Professor Emma Boyland

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