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Junk food advertising ban on public transport linked to a reduction in obesity, study suggests

Junk food advertising ban on public transport linked to a reduction in obesity, study suggests

Restrictions on junk food advertising on Transport for London (TfL) networks have prevented almost 100,000 cases of obesity and could save the NHS £200m, researchers have claimed

Since the 2019 restriction on junk food advertising across the TfL network, researchers from the University of Sheffield and London School of Hygiene & Tropical Medicine (LSHTM) estimate there has been a 1,000 calorie decrease in unhealthy purchases in people’s weekly shopping.

The study, published in the International Journal of Behavioural Nutrition and Physical Activity, suggested that limiting the advertising of high fat, salt and sugar products on transport networks significantly impacted people from deprived areas.

The researchers surveyed 1,970 people about their weekly food shops and compared trends seen in London households with trends seen in the north of England, where there were no restrictions on advertising.

Using a health economic model, the researchers estimated the health benefits, cost savings and equity impacts of the TfL policy.

The modelling suggests that the policy has resulted in 94,867 fewer cases of obesity, 2,857 cases of diabetes prevented or delayed, and 1,915 fewer cases of cardiovascular disease. This was based on comparing expected trends in NHS weight and health data.

Obesity rates increased in both geographical areas of the study; however, a smaller increase was found in the London participants exposed to the advertising restrictions compared with the North of England unexposed participants.

However, over the last decade, the prevalence of childhood obesity has risen by 1.9 percentage points in both London and England overall.

Britain has one of the highest obesity rates in Europe, with two in three adults overweight or obese, and Government figures suggest the NHS spends £6.1bn on obesity-related illnesses in 2014/15. 

Policies aimed at restricting advertisements for high fat, salt and sugar products were a significant part of the recent Tackling Obesity policy paper, and in 2019, TfL implemented advertising restrictions on high fat, salt and sugar products.

However, very few studies have looked at the health and economic impact of out-of-home advertising restrictions.

‘We all know how persuasive and powerful advertising can be in influencing what we buy – especially the food we eat,’ said Dr Chloe Thomas from the University of Sheffield. ‘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.’

The researchers acknowledge considerable uncertainty within data, particularly in the assumption that calorie purchase equates to calorie consumption.

Their analysis found that more significant effects were observed in people who used public transport regularly, suggesting that the advertising policy was indeed the reason for the different, although they stressed that other strategies will also be required if obesity levels are to be actively reduced.

Professor Steve Cummins from LSHTM added: ‘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.

‘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.’

This comes after research last month revealed over a quarter of children are dieting, including children of a healthy weight, amid a ‘steady rise’ in the number of children with overweight and obesity in England.




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