Nutrient-sensitive approach for sustainability assessment of Australian macronutrient dietary recommendations

Background: Dietary guidelines that form the basis for food and nutrition policies in most countries are focused mainly on the social dimensions of health. Efforts are needed to incorporate environmental and economic sustainability. As the dietary guidelines are formulated based on nutrition principles, understanding the sustainability of dietary guidelines in relation to nutrients could support the better incorporation of environmental and economic sustainability aspects into dietary guidelines.

Objectives: This study examines and demonstrates the potential of integrating an input-output analysis with nutritional geometry to assess the sustainability of the Australian macronutrient dietary guidelines (AMDR) relating to macronutrients.

Methods: We used daily dietary intake data of 5345 Australian adults from the most recent Australian Nutrient and Physical Activity Survey 2011-2012 and an input-output database for the Australian economy to quantify the environmental and economic impacts associated with dietary intake. Then, we examined the associations between environmental and economic impacts and dietary macronutrient composition using a multidimensional nutritional geometry representation. Thereafter, we assessed the sustainability of the AMDR regarding its alignment with key environmental and economic outcomes.

Results: We found that diets adhering to the AMDR were associated with moderately high greenhouse gas emissions, water use, cost of dietary energy, and the contribution to wages and salaries of Australians. However, only about 20.42% of respondents adhered to the AMDR. Furthermore, high-plant protein diets adhering to the lower limit of recommended protein intake in the AMDR were associated with low environmental impacts and high incomes.

Conclusions: We conclude that encouraging consumers to adhere to the lower limit of the recommended intake of proteins and meeting the protein requirement through protein-dense plant sources could improve dietary environmental and economic sustainability in Australia. Our findings provide a means of understanding the sustainability of dietary recommendations concerning macronutrients for any country where input-output databases are available.