Testing the price and affordability of healthy and current (unhealthy) diets and the potential impacts of policy change in Australia

Affordability of healthy (recommended) and current (unhealthy) diets

Findings suggest that a healthy diet consistent with Australian Dietary Guidelines [4] is presently affordable for families on a median income costing approximately 18 % of disposable income, but is much less affordable for low income families, costing around 28 % of their household disposable income (Table 6). In comparison, current (unhealthy) diets cost around 20 % of the income of a family of median income and 32 % of the income of low income families (Table 6).

These results are consistent with household expenditure survey data [30] which showed that 16.5 % of average equivalised disposable income was spent on food and drink in all Queensland households, but at 21–41 % of disposable income of low income households, are higher than the equivalised proportion (19.5 %) reported for these households in another study [29]. Disparities are likely to be due to different methodologies, but the amounts spent on food and drink per week in the official reports [29, 30] (for example $79 per week for an unemployed single person) are very low suggesting very restricted diets, and do not concord with prices of the mean quantities of food and drink reported in the AHS [3].

Our findings are similar to those community studies of the affordability of selected ‘healthier’ diets (i.e., not necessarily consistent with dietary recommendations) which cost between 28 % and 40 % of the disposable income of lowest income families, compared with 20 % for families on the average income [7] and up to 48 % of income if environmental sustainability of the diet is also considered [5]. In Aboriginal and Torres Strait Islander communities in Australia, depending on location, it has been estimated that at least 34 %-80 % of the family income is needed to purchase healthy diets [9, 36]. At least 3.7 % of Australian households report having run out of food in the previous 12 months and not being able to afford to buy more [3, 6]. This proportion is higher among some groups, affecting more than one in in five Aboriginal and Torres Strait Islanders (22 %) [37], around 11 % of those unemployed and 16 % of rental households [6].

Internationally there is no accepted benchmark for affordability of a healthy diet [7]. One of the proposed equity targets to close the gap on Indigenous disadvantage in Australia was that, by 2018, 90 % of Indigenous families could access a healthy food basket for under 25 % of their disposable income [38]. A figure of 25 % seems reasonable as a working estimate given the competing priorities for other essential items in the household budget, such as housing, transport, health services, clothing and utilities [29].

The fact that current (unhealthy) diets including alcoholic drinks cost more than healthy diets in Australia, may mask the fact that, at 28 % of income, healthy diets are already unaffordable for low income families in Australia, and reinforces the notion that, if we are not to worsen diets and increase the prevalence of diet-related chronic disease in Australia, price-elasticities must be considered very carefully before food prices are changed in Australia, as proposed under potential changes to the Australian Tax System [20]. Quantitative modelling of the impacts of such strategies requires an understanding of own-price elasticities (how consumption changes with an item’s own price) and cross-price elasticities (how consumption of an item changes with changes in the price of another good) in different groups [39, 40]. An additional consideration for food price elasticities is whether the cross-price elasticities are within the same or different food groups [18]. Plausible food price elasticities have been estimated for use in Australia and New Zealand [40] and globally [41] and could be used to model the consumption and consequent health impacts of the changing prices estimated under various policy scenarios in future studies.

The poor quality of the current Australian diet is consistent with high risk of diet-related disease, especially those mediated by obesity, including type 2 diabetes, cardiovascular disease and some cancers [4] and represents a significant threat to Australia’s health, economic and broader social systems [1, 4]. Therefore it is critical that no additional barriers, such as increased cost of healthy foods, are put in the way of Australians choosing healthier foods and diets.

The findings suggest that more needs to be done to promote healthy diets, including disseminating the fact that they can be less expensive than current dietary patterns. Healthy budgeting programs such as FOODcents may be useful in this regard [42]. Affordability of healthy foods among lower income groups could be improved by promoting cheaper options that are still healthy, such as local specials and seasonal or irregular shaped fresh produce. It is also likely that barriers to healthy choices, such as low food literacy and poor cooking skills, also need to be addressed [4, 43]. However, there is mounting evidence that current “food environments exploit people’s biological, psychological, social and economic vulnerabilities, making it easier for them to eat unhealthy foods” [44] and that “regulatory actions from governments and increased efforts from industry and civil society will be necessary to break these vicious cycles” [44].