By Dr Emma Boyland, Senior Lecturer, University of Liverpool

That the intention of advertising is to influence an audience shouldn’t need saying. Basic market rules dictate that if advertising wasn’t effective in influencing us, then it wouldn’t exist.

As an academic psychologist, I’ve spent my career researching the impact of food advertising on children’s food preferences and intake. Research has repeatedly demonstrated that exposure to unhealthy food advertising has a negative impact on children’s diets, which is why I am fully behind a 9pm watershed on junk food adverts on TV and online.

The Government’s ambition with this policy is to protect children from the harmful effects of junk food adverts. Their analysis of a 9pm watershed on junk food adverts indicates that the health benefits associated with reductions in obesity-related ill health over children’s lifetimes will be worth around £1.9 billion, which makes this policy the right thing to do from a financial perspective, as well as the moral one.

But the Government has been short-sighted in deciding to exclude the impact on adults in their cost-benefit analysis. A 9pm watershed on TV and online would also restrict adults’ exposure to junk food advertising.

The Obesity Health Alliance commissioned me to review existing evidence on the impact of advertising on adults. This is available here.

Although limited, especially relative to the scale of data on the impact of advertising to children, recent evidence from well-controlled studies shows that exposure to food advertising does influence adults in terms of their desire to eat and also what and how much they eat.

We can also learn from studies exploring how other types of advertising for unhealthy products influences adults’ behaviour. There is a growing body of evidence to demonstrate that alcohol marketing is associated with greater, and more risky, alcohol consumption in UK adults. It is likely that we can apply similar conclusions to the impact of unhealthy food advertising on adults.

Given that over a quarter of adults in England are living with obesity, and excess weight is associated with a number of diseases including Type 2 diabetes, cancer, heart disease, liver disease along with mental health conditions, a reduction in adult obesity and subsequent health benefits would reap significant savings to the NHS.

As the consultation on restricting unhealthy food advertising draws to a close, it is likely that the food and media industry will be making a persuasive case that further restrictions will represent a cost burden to their businesses. While this does need to be considered, it is vital that the full benefits of less junk food advertising exposure for everyone is taken into account. It’s often said that you can’t put a price on good health – but this is one situation where, for the good of the health of the nation and the NHS, we need to.