Jamie Oliver’s introduction of a sugar tax in his restaurants helped cut the sale of added-sugar beverages by more than 10%, according to researchers, although sales did begin to creep up over time.
A study by the London School of Hygiene & Tropical Medicine and the University of Cambridge found introducing 10p per drink to the price of added-sugar drinks in Jamie’s Italian restaurants across the UK contributed to a significant decline in sales.
After adjusting for general trends in sales, it found that adding a 10p levy to sugar-sweetened beverages sold in 37 of the restaurants, combined with activities such as redesigning menus, offering new lower-sugar drinks and related publicity, was associated with an 11% decline in sales per customer, 12 weeks after the levy was introduced.
A decline in sales of 9.3% per customer was still observed six months after the September 2015 levy was introduced.
The authors said further research with a longer follow-up was required to assess whether the pattern would be sustained.
Steven Cummins, professor of population health at the London School of Hygiene & Tropical Medicine, who led the study, said: “Obesity, type 2 diabetes and cardiovascular disease are among the most pressing global health challenges facing the world today. Evidence suggests that excessive consumption of sugar-sweetened beverages is an important contributor to these potentially life-threatening conditions but we still don’t have a clear answer on how best to encourage people to consume fewer of them.
“Our study showed that a combination of the levy, menu changes and clearly explaining to customers why it was introduced, and that the proceeds would go directly to a worthy cause, looks to have had a relatively large effect on consumer behaviour given the small size of the levy. This type of ‘complex intervention’ has also been shown to be successful in economic studies of levies on alcohol.”
The study also found there was an overall decrease in the numbers of non-alcoholic beverages sold per customer, with the exception of fruit juice, which increased by 22% after six months. Sales of diet cola and bottled waters also declined.
Professor Cummins said: “A possible reason for this decline could be that more people were choosing tap water, but data on tap water orders was not available as it was not recorded on the restaurant’s sales system. Overall, our study suggests that a small levy on sugar-sweetened drinks sold in restaurants, coupled with complementary activities, may have the potential to change consumer behaviour and reduce the consumption of these drinks, which are associated with major health risks.”
Assistant professor in public health economics Dr Laura Cornelsen co-led the study. She said: “This study raises interesting questions about how fiscal interventions may work beyond the effect of the price increase. For example, how big a role did the menu change or the text introducing the levy play? Taxes and levies on sugar-sweetened drinks are regularly framed as health-related measures and such framing might be having an effect of its own, including on both the quantity and the range of beverages sold.”
The research comes ahead of the introduction of the government’s Soft Drinks Sugar Levy in April 2018.
The levy will see a rate of 18p/litre for drinks with 5g-8g of sugar per 100ml and a higher rate charge of 24p/litre for drinks imposed on suppliers, although it is not clear if suppliers and retailers intend to pass on the costs to consumers.
The London School of Hygiene & Tropical Medicine has a long track record of clashing with the soft drinks industry and food and drink bosses in general.
It has previously produced research slamming the food and drink industry’s record in tackling obesity, with a series of reports attacking the weakness of the Responsibility Deal, of which Oliver has also been a major critic.
The drinks industry has repeatedly disputed evidence that sugar taxes have been successful where introduced in other countries such as Mexico.
The government and Public Health England claim the looming tax has forced a recent wave of reformulation among suppliers.