Highlights
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Summary
Background
Policies have been proposed to restrict the marketing of products high in fat, salt and sugar as a way to improve the population’s diet and reduce obesity. In 2019, Transport for London implemented advertising restrictions on products high in fat, salt and sugar. A controlled interrupted time series analysis comparing London with a northern England control suggested that advertising restrictions had resulted in a reduction in household energy purchases.
The aim of the study presented here was to estimate the health benefits, cost savings and equity impacts of the Transport for London policy using a health economic modeling approach, from the perspective of the English National Health Service and personal social services.
Methods
A diabetes prevention microsimulation model was modified to incorporate the London population and the Transport for London advertising intervention . The conversion of calories into reduction in body mass index was mediated by a mathematical model approximation that estimated weight loss.
Outcomes collected included incremental obesity, long-term diabetes and cardiovascular disease events, quality-adjusted life years, healthcare costs saved, and net monetary benefit. The inequality slope index was calculated for the proportion of people with obesity across all socioeconomic groups to assess equity impacts.
Results
Results show that the Transport for London policy was estimated to result in 94,867 (4.8%) fewer people with obesity and reduced the incidence of diabetes and cardiovascular disease by 2,857 and 1,915 cases, respectively, within three years of the intervention.
The policy would deliver approximately 16,394 additional quality-adjusted life years and save £218 million in NHS and social care costs over the lifetime of the current population. Individuals in the most socioeconomically disadvantaged groups were expected to achieve greater benefits (e.g., 37% greater gain in quality-adjusted life years) compared to the least disadvantaged.
Image : Modeled reduction in expected disease outcomes with the Transport for London intervention.Expected number of cases of obesity and overweight at one year with (red bars) and without (black bars) intervention in A all of London, B per 100,000 people in each IMD quintile. C Obesity over time in London with (red) and without (black) intervention. D Slope of inequalities for obesity across IMD quintiles for intervention (red) and control (black) scenarios, with data shown as solid line and linear slope as dashed line. Expected reduction in EF) cases of cardiovascular disease (CVD), or GH) new cases of type 2 diabetes, in E,G) all of London, F,H) per 100,000 people in each IMD quintile, over a period of 20 years horizon
Conclusions
This analysis suggests that restricting advertising of products high in fat, salt and sugar has considerable health and economic benefits. The economic and population health impacts of Transport for London ’s advertising restrictions are likely to have reduced health inequalities in London.
Comments
Restrictions on junk food advertising on Transport for London (TfL) networks have prevented almost 100,000 cases of obesity and are expected to save the NHS more than £200 million, according to new research.
The new study, from the University of Sheffield and the London School of Hygiene and Tropical Medicine (LSHTM), revealed that TfL’s advertising policy restricting advertising of foods high in calories from sugar and fat or high in salt has led consumers to cut back on less healthy products.
Researchers estimate that the policy, which has been in place since 2019, has directly led to 94,867 fewer cases of obesity than expected (a 4.8% decrease), 2,857 fewer cases of diabetes, and 1,915 fewer cases of cardiovascular disease.
As well as the benefits to people’s health, the analysis found that the current advertising policy would save the NHS £218 million over the lifetime of the current population.
The study is published in the International Journal of Behavioral Nutrition and Physical Activity , and is led by the University of Sheffield in collaboration with researchers from the London School of Hygiene & Tropical Medicine (LSHTM), who previously found that advertising policy has contributed to a decrease of 1000 calories in energy from unhealthy purchases in consumers’ weekly purchases.
By seeing what consumers buy in their weekly grocery stores through surveys and comparing trends in London with a control group of households outside London where there were no restrictions on advertising, academics were able to assess the effect that the policy is having on people’s health and the health service.
Dr Chloe Thomas, first author of the study 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 in the foods we eat. Our study has shown what an important tool advertising restrictions can be in helping people live healthier lives without costing them more money.
“We hope that demonstration of the significant benefits of the policy in preventing obesity and diseases exacerbated by obesity will lead to it being implemented on a national scale, something that could save lives and NHS money.”
The findings reveal that the policy has had the greatest impacts on the health of people from deprived areas in terms of preventing health conditions, thereby reducing the level of health inequality in London. Even though middle-income people cut more calories, the policy has had a greater impact on more deprived areas, as people in those areas tend to be less healthy overall.
Professor Steve Cummins, of LSHTM, said: "This work shows the potential health impacts and cost savings of the Mayor of London’s ’Junk Food Ads Restriction’ based on our evaluation earlier this year, published in PLoS Medicine, which found that the policy reduced average household energy purchases by 1,000 calories per week.
“With more than 80 local authorities across the UK considering implementing similar policies, this study provides further evidence of the effectiveness of advertising restrictions to help decision makers. In light of the government’s current delay in implementing obesity prevention policies outlined in the recent Health and Care Act 2022, this is a policy that local authorities can now implement without the need for national regulation in a effort to address obesity on a national scale.”
The findings come at a time when food and diet are firmly on the minds of many families in Britain: the government recently announced its Food Strategy, which has come under intense scrutiny for not going far enough to address the concerns about food safety in the UK.
London Mayor Sadiq Khan said: “Advertising undoubtedly plays an important role in promoting and encouraging the consumption of less healthy foods. With childhood obesity putting the lives of young Londoners at risk, it is simply not right that children and families in the capital are regularly inundated with adverts for foods that are not good for their health; That is why it was clear that strong measures were needed.
“This study, which builds on research from earlier this year, demonstrates once again that the innovative restrictions we introduced could not only influence behavior 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, relieve some of the burden on our overstretched health service and build a better London for everyone.”
Dr Penny Breeze, lead researcher on the study from the University of Sheffield’s School of Health and Related Research (ScHARR), added: “There have been very few studies that have looked at the health and economic impact of advertising restrictions. out of home. “We are delighted to show that there are many benefits to the policy and hope that the policy continues to be implemented outside of London.”
