Removing Snack Foods From Tills Could Improve Eating Habits

Liam Davenport

December 19, 2018

The amount of unhealthy snacks bought by shoppers every year could be reduced dramatically by introducing policies aimed at removing sweets and crisps from supermarket checkouts, say UK researchers.

Jean Adams, from the Centre for Diet and Activity Research at the University of Cambridge, and colleagues looked at data on shopping habits from 2013 to 2017, comparing them across supermarkets that did and did not introduce checkout food policies.

They found that purchases of sugary foods, chocolate and crisps in supermarkets that introduced such policies fell by more than 17% in the first month, and more than 15% after the first year, compared with supermarkets that did not.

The research, which was published online by PLOS Medicine on 18th December, also indicated that spontaneous, 'on the go' purchases eaten without being taken home were reduced by 76%.

Relatively Simple Intervention

Lead author Katrine Ejlerskov, also from the University of Cambridge, said in a news release: "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."

Describing that as "a relatively simple intervention", she continues: "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."

Adams added: "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.

"One such intervention might be to introduce nutritional standards for checkout food as suggested in the Government's recent Childhood Obesity Plan," Adams noted.

"Such a government-led policy might prove attractive to supermarkets as it would provide a level playing field across the sector."

Impulse Buys

Supermarket chains such as Tesco, Asda, and Morrisons have captured a large share of the grocery market in the UK, and play a "major role" in how food preferences and purchasing behaviour are shaped, the researchers say.

One such example is the positioning of foods at supermarket checkouts as customers have to pass them to pay and can spend a considerable amount of time in queues.

Checkout displays have been the focus of much attention from advocacy groups, the media, and researchers in recent years, who have voiced concerns over the nutritional quality of food available at checkouts.

"Many snacks picked up at the checkout may be unplanned, impulse buys, and the options tend to be confectionary, chocolate or crisps," Adams said in the news release.

"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."

Spending Data

As it was not possible to conduct a randomised controlled trial, the researchers used a natural experimental design to analyse data from a UK commercial household purchase panel on 27,385,050 households for the period January 2013–February 2017.

The researchers determined 4-weekly purchases of common checkout foods before and after implementation of checkout food policies, examining the results at 4 weeks and 12 months post-implementation.

Data on foods bought and eaten 'on the go' during 2016/17 was also collected. This involved 7500 individuals and was weighted to correspond to the total UK market of 50,398,000 individuals aged 13–79 years.

The team focused on purchases of sugary confectionary, chocolate, and potato crisps, and synthesised the results across supermarkets using meta-analyses.

They looked at nine national supermarkets that cover more than 90% of the UK grocery market: Aldi, Asda, Co-op, Lidl, M&S, Morrisons, Sainsbury's, Tesco, and Waitrose.

Of those, six implemented checkout food policies between January 2014 and July 2016 and were deemed 'intervention' supermarkets, while the remaining three supermarkets acted as comparators.

The team calculated that implementation of checkout policies was associated with a significant reduction in purchases of common checkout foods, at 157,700 fewer packages per percentage market share at 4 weeks and 185,100 fewer packages per percentage market share at 12 months.

This equated to a reduction in the weighted average change in purchases related to comparator supermarkets of 17.3% at 4 weeks and 15.5% at 12 months.

When looking at foods bought and eaten 'on the go', the researchers found that there were 76.4% fewer annual purchases of less healthy common checkout foods from supermarkets with checkout food versus those without.

Study Limitations

Adams and colleagues concede that there are several limitations to the analysis, including that they do not know where about in the supermarket purchases were selected from, and that other interventions may have led to the reductions.

Nevertheless, they write that "our findings suggest checkout food policies may be one method to help decrease some purchases of less healthful foods".

They add: "Government-led nutritional standards on checkout food have been suggested and may be attractive to retailers as they provide a 'level playing field'."

The researchers suggest that future studies "should prospectively explore how supermarkets and customers change their behaviour in response to supermarket-led interventions such as checkout food policies".

"Data on the effect of such policies on total diet would allow us to understand their potential for improving population health."

The team also call for "qualitative data exploring consumers' views of the retail environment and supermarkets' motivations for introducing policies", as this "may help to identify further opportunities for greater alignment between retail and public health policy".

Four authors received funding for this work from the Public Health Research Consortium, a Policy Research Unit, funded by the Department of Health and Social Care, UK. Adams and Martin White receive salary funding from the Centre for Diet and Activity Research (CEDAR), a UK Clinical Research Collaboration (UKCRC) Public Health Research Centre of Excellence. This grant is administered by the UK Medical Research Council, but funding is from a consortium of funders: the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UKCRC.

No conflicts of interest declared.

PLOS Medicine 2018. doi: 10.1371/journal.pmed.1002712


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