Preaching the benefits of healthy eating has little point when the cost of purchasing healthy foods in South Australia can cost as much as a third of a low-earner's income, according to Flinders University researchers.
A new public health study has found that the comparatively higher cost of eating a nutritious and well-balanced diet can be prohibitively expensive for people on low incomes, and is likely to drive them towards cheap, processed foodstuffs with high fat, salt and sugar content.
The study, led by the Head of the Discipline of Public Health, Professor Paul Ward, surveyed the cost of a weekly "shopping basket" of readily available healthy foods purchased in metropolitan Adelaide and rural centres in South Australia.
"You read a lot in the media about housing stress, but it applies to food as well," Professor Ward said.
In the case of welfare recipients, over a third of their disposable income is required to purchase healthy foods. In stark contrast, Professor Ward said, the proportion of income required to eat healthily by the top third of income earners is about nine per cent.
"With increasing obesity, governments tend to focus their attention on telling people to eat healthy, but the problem is that the more unaffordable healthy food becomes, then the more difficult it becomes for individuals to take the healthy eating option," he said.
"If it's chewing up a third of your income to potentially eat healthily, and you have increasing utility bills and rental or mortgage payments, something's got to give.
"It's easy for governments to say that it's an individual choice to eat unhealthily, but the research shows that it's not a choice but an individual difficulty because of how much food costs.
The next step is to buy energy-dense but nutrient-poor food, because that is all they can afford."
Food is becoming more expensive because of issues that include drought and flooding as well as increased shipping and transport costs.
"These are real costs that producers have to pass on to consumers," Professor Ward said. And because of intrinsic factors such as the short shelf life of fresh fruit and vegetables, the price of healthy foods rises more steeply than that of processed foods.
Professor Ward said that to combat potential health problems such as obesity and diabetes, some governments overseas were trialling programs that reduced the costs of healthy foods in low-income areas.
"That approach has been shown to be effective in increasing the purchase of healthy foods in those locations," he said.
Professor Ward said other research that models the consequence of increased uptake of healthy foods shows marked long-term reductions in diet-related disease including diabetes and some cancers.
"The long-term impact of something pretty straightforward is very powerful," he said.
"Food Stress in Adelaide: The Relationship between Low Income and the Affordability of Healthy Food" is published in the Journal of Environment and Public Health.
More information: www.hindawi.com/journals/jeph/2013/968078/