Hard Evidence: do supermarket checkouts make kids obese?

We think checkouts influence obesity but does it? Jurijus Azanovas

Your eye gets caught by the dried apples slices and pistachios but your child, sitting in the trolley, sees the Percy pig sweets. The queue is moving slowly, how well do you resist?

A commentary by Deborah Cohen published in the New England Journal of Medicine suggested that shoppers’ ability to resist palatable foods goes down if they are tired, stressed or have just been faced with a lot of cognitive choices. In these cases, the lure of the checkout becomes even more tempting. As a parent you decide what your child eats but this can be strongly influenced by pestering.

There is palpable concern. This autumn, the Junk Free Checkouts campaign was launched to remove unhealthy snacks from checkouts and campaigners are calling for government action. They are backed by a nationwide survey finding that 90% of people think junk food at the checkout contributes to obesity in both adults and children, and 75% of parents have given in to their children and purchased something due to being pestered.

An annual survey of 48 branches of 14 national supermarkets and high street chains by the Children’s Food Campaign the previous year found that although Co-op and Marks & Spencer also had more healthy snacks near the till and Lidl had trialled “guilt free” lanes, many others had barely improved at all since the first survey was carried out ten years ago.

The obesity trend

Childhood obesity is an increasing phenomenon, according to Health Survey for England (HSE) figures. Obesity among two to ten-year-olds rose from 10.1% in 1995 to 13.9% in 2011 and obesity prevalence among 11 to 15-year-olds was 20.2%.

Health Survey for England

Although there are growing indications that the previous upwards trend may now be flattening out, it is still too early to be sure that this represents a long-term change in the child obesity trend. The World Health Organisation called obesity a global epidemic with special concern for the increasing incidence of child obesity.

‘Eye level is buy level’

Relatively little is known in terms of the role that children play in influencing parents at the checkout, as Claus Ebster and colleagues at the University of Vienna discussed in their research in 2009. Their findings suggested that twice as many purchases in supermarkets are triggered by children than their parents are aware of. The retail adage that “eye level is buy level” can apply as much to children as adults.

They also found that children aged between three and seven who were also not restricted by being in a shopping trolley or pushchair made more purchase requests. However, parents were more likely to yield to an in-store request if that request was made early in the shopping trip and if it was an appeal rather than a demand.

Healthier snacks at the till

In the US, research in low-income neighbourhoods that looked at increasing health food availability gave conflicting results. As indicated in Glantze’s review, although sales, knowledge, purchasing and consumption of healthier foods all increased, no significant change in weight was found when Body Mass Index (BMI) was investigated before and after these interventions. But other research on energy dense snack foods found a small positive correlation with BMI.

The results of a Californian test store that set up healthy checkout aisles hasn’t yet reported results, but Glantz and colleagues recommend placing multiple healthy checkout aisles in store to shift the healthy/unhealthy balance. It’s clear the results of doing this would need rigorous evaluation.

An interesting small study of parents of obese and non-obese children in the Journal of Pediatric Nursing this year suggested that although mothers felt competent and had the ability to take preventative steps against child overweight, they didn’t always feel they had the energy to do so. So stocking more healthy choices at the checkout and limiting the availability of high-fat and sugar foods could help. This would be a great example of nudge strategy – encouraging healthy snacks without removing choice.

A lucrative space

Ranged against the ideals of dieticians and nutritionists is the power of the checkout to deliver a sales for supermarkets and manufacturers. According to a recent study by the EHI Retail institute for Wrigley’s German subsidiary, this is actually underexploited. The report suggested checkout zones generated a sales returns of €35,000 ($47,000) per square – seven times the average for an entire store. And although checkouts accounts for only 1% of sales space, they generated more than 7% of total sales.

Other research suggested that end of aisle items accounted for as much as 30% of supermarket sales, so much so that manufacturers pay “slotting fees” to secure those spots.

The Wrigley report suggests converting the 85% of occasional or non-purchasers into regular checkout purchasers and although arguably gums are a far healthier preference than mints, candies, chocolate bars and other sweets, it would be useful for those involved in the current public health campaign to be aware of new marketing and design strategies by food companies to increase sales. One “tactic” highlighted by campaigners was to place certain items and child level.

The need for a firm government commitment is at least encouraging; the Department of Health recently announced that food promotion is back on the agenda of the Responsibility Deal, the agreement between government and manufacturers to tackle big health issues like obesity. But the publication of the junk food campaign’s wall of fame and shame show they and retailers still have some way to go because after three months, only one supermarket has made a change.

It seems unhealthy food is therefore a driver in unhealthy eating in children. While having snacks there does make children and parents more inclined to buy, the research is still young. What is clear is that we need more choice, because the upward trend in childhood obesity shows we have a real problem.

Hard Evidence is a series of articles in which academics use research evidence to tackle the trickiest public policy questions.