Supermarkets - convenience at a cost

They are undoubtedly convenient, but supermarkets’ size and sales strategies are contributing to our nation’s obesity levels, claims Deakin’s epidemiologist Dr Adrian Cameron, who is seeking ways to help supermarkets have a more positive influence on our national diet.

Dr Cameron is a Senior Research Fellow with the WHO Collaborating Centre for Obesity Prevention (based in Deakin Population Health) and has just been awarded the 2015 Konrad Jamrozik Prize, for his public health advocacy.

The award was presented in Hobart in early September at the Population Health Congress, a three-yearly conference of the Public Health Association of Australia, the Australasian Epidemiological Association, the Australian Health Promotion Association and the Australasian Faculty of Public Health Medicine.

The award recognises innovative efforts to address a major public health issue through application of the best available evidence, and a courageous commitment to advocacy, and was created in honour of Australian public health trailblazer, Professor Konrad Jamrozik - a researcher, teacher, fearless tobacco control advocate and “much loved character.”

Dr Cameron explained that an unhealthy diet is the "number one" health risk factor in Australia, and responsible for a global obesity epidemic that is currently affecting more than 500 million people and is accompanied by health risks, such as diabetes, heart disease, stroke and cancer.

Since he joined Deakin from the Baker IDI Heart and Diabetes Institute in 2009, he has been researching the influence of supermarkets on our diets.

“Sixty-three per cent of all food purchased in Australia is bought in supermarkets, but we have tended to overlook their role in the battle against obesity,” he said.

“Yet our research shows that the food environment is a key driver of eating behaviour. Even small changes can have a big impact.”

Dr Cameron has also found that stores behave differently, depending on the socioeconomic status (SES) of the local population, with lower SES stores more heavily promoting junk food, such as soft drink, chips, chocolate and lollies.

“There is an argument that the stores promote what they are most likely to sell, but this is only half the truth. They also have a responsibility to make the healthy choice the easier choice,” he said.

In a highly significant research project, Dr Cameron and Dr Lukar Thornton from Deakin’s Centre for Physical Activity and Nutrition (C-PAN) led an international study of supermarkets in eight countries with comparable diets – the USA, UK, the Netherlands, Sweden, Canada, NZ, Denmark and Australia.

“We discovered a direct correlation between supermarket size and obesity prevalence,” he said. “In large supermarkets people tend to buy in bulk. They shop less frequently, are less likely to buy fresh food, and are confronted with more junk food.

“Large supermarkets appear to be an indicator of a food and shopping culture that encourages obesity.”

Large Australian supermarkets were shown to have more soft drinks, confectionery and chocolate at checkouts and end-of-aisle displays than the other seven countries. Only New Zealand and the US have bigger supermarkets than Australia – but these two countries are also the only two that have a higher prevalence of obesity than Australia.

“There is an almost perfect correlation between how big a country’s supermarkets are and obesity numbers. There may be other explanations for this association, but the link between shopping less often and buying less healthy foods strongly suggests that store size is a big part of the problem.”

In a joint VicHealth-funded project with the City of Greater Bendigo, Dr Cameron and Deakin's Dr Gary Sacks are currently working with a regional chain of supermarkets to understand the influence of supermarket promotions, such as check-out displays, aisle placement and island bins, on consumer behaviour, and introducing a series of interventions to change store and customer behaviour.

“To change the way our supermarkets promote healthy eating, we need evidence,” he said.

“If we can show supermarkets that they can be just as profitable, or more profitable, by promoting healthy food that would go a long way to influencing their promotional practices.”

This project is designed to show that scalable, sustainable and cost effective interventions can have an impact on what people buy. Dr Cameron hopes that evidence from trials such as this can lead to an improved food environment across the nation and beyond.

• Read more in “The Conversation.”
• Dr Cameron will be interviewed on ABC Radio National by Patricia Karvelas on October 5, 7.15pm.