The study, published in the journal PLOS Medicine, found that 76% fewer purchases of sugary confectionary, chocolate and potato crisps were bought and eaten 'on-the-go' from supermarkets with checkout food policies compared to those without. In addition, 17% fewer small packages of these items were bought and taken home from supermarkets immediately after introducing a checkout food policy.
Large supermarket chains such as Tesco, Asda and Sainsbury's have captured the majority of the grocery market and play a major role in shaping food preferences and purchasing behaviour. Retail practices such as product displays, positioning, promotions and pricing can all influence consumers' choices in stores.
Supermarket checkouts provide a unique location for prompting purchases as all customers have to pass through them to pay and may spend considerable time in queues; however, the majority of food at supermarket checkouts could be considered unhealthy. Over the last decade, many UK supermarket groups have made voluntary commitments to remove or limit unhealthy foods at the tills or to provide healthier options.
'Many snacks picked up at the checkout may be unplanned, impulse buys - and the options tend to be confectionary, chocolate or crisps,' says Dr Jean Adams from the Centre for Diet and Activity Research at the University of Cambridge. 'Several supermarkets have now introduced policies to remove these items from their checkouts, and we wanted to know if this had any impact on people's purchasing choices.'
To examine the effect that the introduction of checkout food policies in major supermarket chains has had on shoppers' purchasing habits, Dr Adams led a team of researchers at the universities of Cambridge, Stirling and Newcastle who analysed data from the Kantar Worldpanel's Consumer panel for food, beverages and household products. Six out of the nine major supermarkets introduced checkout food policies between 2013 and 2017. (The researchers anonymised the information to avoid 'naming and shaming' companies.)
Firstly, the team looked at how purchases of less healthy common checkout foods brought home changed following the implementation of checkout policies. They used data from over 30,000 UK households from 12 months before to 12 months after implementation.
The researchers found that implementation of a checkout food policy was associated with an immediate 17% reduction in purchases. After a year, shoppers were still purchasing over 15% fewer of the items compared to when no policy was in place.
Next, they looked at data from 7,500 shoppers who recorded food bought and eaten 'on-the-go' during 2016-17 from supermarkets with and without checkout food policies. On-the-go purchases are often impulsive and can be the result of children pestering their parents. The researchers found that shoppers made 76% fewer annual purchases of less healthy common checkout foods from supermarkets with checkout food policies compared to those without.
As the study was not a randomised control trial, it was not possible to say definitely that the changes in purchasing behaviour were due to the checkout food policies. Stores that chose to have checkout food policies may have been different from those that did not. Or shoppers may have changed to purchasing larger packages from the same stores, or similar products from stores that aren't supermarkets.
'Our findings suggest that by removing sweets and crisps from the checkout, supermarkets can have a positive influence on the types of purchases their shoppers make,' says Dr Katrine Ejlerskov, the study's first author. 'This would be a relatively simple intervention with the potential to encourage healthier eating. Many of these purchases may have been impulse buys, so if the shopper doesn't pick up a chocolate bar at the till, it may be one less chocolate bar that they consume.'
'It may seem obvious that removing unhealthy food options from the checkout would reduce the amount that people buy, but it is evidence such as this that helps build the case for government interventions to improve unhealthy behaviours,' adds Dr Adams.
'One such intervention might be to introduce nutritional standards for checkout food as suggested in the Government's recent Childhood Obesity Plan. Such a government-led policy might prove attractive to supermarkets as it would provide a level playing field across the sector.'
The work was undertaken by the authors as part of the Public Health Research Consortium. The Public Health Research Consortium is funded by the Department of Health and Social Care Policy Research Programme.
Ejlerskov, KT et al. Supermarket policies on less healthy food at checkouts: natural experimental evaluation using interrupted time series analyses of purchases. PLOS Medicine; 18 Dec 2018; DOI: 10.1371/journal.pmed.1002712
Press release distributed by Pressat on behalf of Rage Communications, on Tuesday 18 December, 2018. For more information subscribe and follow http://www.pressat.co.uk/