London School of Hygiene & Tropical Medicine

Restrictions for junk food advertising on Transport for London (TfL) networks have prevented almost 100,000 obesity cases and is expected to save the NHS over £200 million, according to new research published in the International Journal of Behavioural Nutrition and Physical Activity.

The study, carried out by the University of Sheffield and the London School of Hygiene & Tropical Medicine (LSHTM), revealed the TfL advertising policy restricting the advertisement of foods high in calories from sugar and fat or high in salt, has led to consumers cutting down on less healthy products.

The team estimated the policy, which has been in place since 2019, has directly led to 94,867 fewer cases of obesity than expected (4.8% decrease), 2,857 fewer cases of diabetes, and 1,915 fewer cases of cardiovascular disease.

In addition to health benefits for individuals, the analysis found the current advertising policy would save the NHS £218 million over the lifetime of the current population.  

The study was led by the University of Sheffield in collaboration with researchers from LSHTM, who previously found the advertising policy has contributed to a 1,000 calorie decrease in energy from unhealthy purchases in consumers' weekly shopping. 

By seeing what consumers are purchasing in their weekly food shops via surveys, and comparing trends in London to a control group of households outside of London where there were no restrictions on advertising in place, the researchers were able to assess the effect the policy is having on people’s health and the health service.

Steve Cummins, Professor of Population Health at LSHTM and study author, said: “This work shows the potential health impacts and cost savings of the Mayor of London’s ‘Junk Food Ad Restriction’ based on our evaluation earlier this year, published in PLoS Medicine, which found that the policy reduced average household purchases of energy by 1,000 calories per week. 

“With more than 80 local authorities across the UK now considering the implementation of similar policies, this study provides further evidence of the effectiveness of advertising restrictions to help support decision-makers. In light of the government’s current delay in implementing obesity prevention policies outlined in the recent 2022 Health & Care Act, this is a policy that local authorities can deliver now without the need for national regulation in an effort to tackle obesity on a national scale.”

Dr Chloe Thomas, study author from the University of Sheffield’s School of Health and Related Research (ScHARR), said: “We all know how persuasive and powerful advertising can be in influencing what we buy - especially the food we eat. Our study has shown what an important tool advertising restrictions can be in order to help people lead healthier lives without costing them more money.

“We hope that demonstrating the policy's significant benefits in preventing obesity and the diseases exacerbated by obesity, will lead to it being rolled out on a national scale, something that could save lives and NHS money."

Sadiq Khan, Mayor of London, said: “Advertising undoubtedly plays a significant role in promoting and encouraging the consumption of less healthy foods. With child obesity putting the lives of young Londoners at risk it simply isn’t right that children and families across the capital are regularly inundated with adverts for foods that do not support their health – that’s why I was clear that tough action was needed.

“This study, which builds on research from earlier this year, demonstrates yet again that the ground-breaking restrictions we introduced could not only influence behaviour and ultimately save lives but could directly save our NHS hundreds of millions of pounds.

“I am determined to continue this work to improve the health of Londoners, alleviating some of the burden on our overstretched health service and building a better London for everyone.”

The policy had the biggest health impacts on people from deprived areas in terms of preventing health conditions, therefore reducing the level of health inequality in London. Despite people on middle incomes cutting more calories, the policy has had a bigger impact on the most deprived areas as people from those areas tend to be less healthy overall.

The findings come at a time when food and diet is firmly on the minds of many families in Britain - the government recently announced its Food Strategy, which has come under heavy scrutiny for not going far enough to address concerns over food security in the UK.

Dr Penny Breeze, lead investigator of the study from the University of Sheffield’s ScHARR, added: “There have been very few studies that have looked at the health and economic impact of out of home advertising restrictions. We are delighted to show that there are many benefits to the policy, and hope that the policy continues to be rolled out outside of London.”

Publication

Chloe Thomas et al. The health, cost and equity impacts of restrictions on the advertisement of high fat, salt and sugar products across the transport for London network: a health economic modelling study. BMC International Journal of Behavioural Nutrition and Physical Activity. DOI: 10.1186/s12966-022-01331-y