A systematic scoping review of the habitual dietary costs in low socioeconomic groups compared to high socioeconomic groups in Australia

Background:
Low socioeconomic groups (SEGs) in Australia are less likely to consume diets consistent with the Australian Dietary Guidelines (ADGs) and suffer poorer health than the broader population. The unaffordability, or perceived high cost, of healthy diets may be a factor. Detailed data on the cost of habitually consumed diets is required in order to inform strategies to alleviate socioeconomic impacts on dietary intake.

This systematic scoping review aims to identify the cost of the habitual dietary intake of low SEGs in Australia, in terms of the whole diet and its composite foods, in comparison to the cost in higher SEGs.

Methods:
A systematic search of peer-reviewed literature since 2000 and key government and non-government organisation (NGO) websites was undertaken. Data were extracted, synthesised and analysed in relation to study populations, dietary cost assessment measures, socioeconomic measures, and dietary cost and affordability.

Results:
The review identified four studies meeting inclusion criteria. Results confirmed that overall, low SEGs spend a lower amount, yet a higher proportion of household income, on food and drinks than higher SEGs. Quantitative comparison of the dietary costs between included studies was not possible due to difference in populations and study metrics. Costs of the habitual diet in these studies were not reported for ADG food groups, so did not allow for assessment of the healthfulness of the dietary intake or comparison with costs of recommended diets at food group level.

Conclusions:
Existing research does not provide sufficiently granular data of the costs of habitual diets of low SEGs in comparison to higher SEGs or data in a form that can inform strategies and interventions to improve dietary intake and diet-related health of low SEGs in Australia. Future empirical health research requires more granular measures of habitual spending on ADG food groups across SEGs.