The affordability of a healthy and sustainable diet: an Australian case study

EAT-Lancet Commission's Planetary Health Diet proposed a diet that integrates nutrition and sustainability considerations, however its affordability is unknown in many country-specific contexts, including Australia. The aim of this study is to develop a healthy and sustainable food basket modelled on the Planetary Health Diet to determine the affordability of the Planetary Health Diet basket across various socio-economic groups, and compare this affordability with a food basket modelled on the typical current diet, in an Australian setting.

An Australian-specific Planetary Health Diet basket was developed for a reference household (2 adults and 2 children) modelled on the Planetary Health Diet reference diet, and compared to a previously-developed Typical Australian Diet basket. The cost of each food basket was determined by online supermarket shopping surveys in low, medium and high socio-economic areas in each Australian state. Basket affordability was determined for the reference household by comparing the basket cost to disposable income in each socio-economic group in each state. Mann-Whitney U tests then determined if there were significant differences between the median costs and the median affordability of both baskets.

The Planetary Health Diet basket was shown to be less expensive and more affordable than the Typical Australian Diet basket nationally, in all metropolitan areas, in all socio-economic groups across Australia (median cost: Planetary Health Diet = AUD$188.21, Typical Australian Diet = AUD$224.36; median affordability: Planetary Health Diet = 13%, Typical Australian Diet = 16%; p = < 0.05).

This study showed the Planetary Health Diet to be more affordable than the Typical Australian Diet for metropolitan-dwelling Australians.

These results can help to inform public health and food policy aimed at achieving a healthy and sustainable future for all Australians, including reductions in overweight/obesity rates and increased food security.