Nutrient-sensitive approach for sustainability assessment of different dietary patterns in Australia

Nutritional, environmental and economic impacts of ultra-processed food consumption in Australia

OBJECTIVE

To quantify the full life cycle impacts of ultra-processed foods (UPF) for key environmental, economic and nutritional indicators to identify trade-offs between UPF contribution to broad-scope sustainability.

DESIGN

Using 24-h dietary recalls along with an input-output database for the Australian economy, dietary environmental and economic impacts were quantified in this national representative cross-sectional analysis. Food items were classified into non-UPF and UPF using the NOVA system, and dietary energy contribution from non-UPF and UPF fractions in diets was estimated. Thereafter, associations between nutritional, environmental and economic impacts of non-UPF and UPF fractions of diets were examined using a multi-dimensional nutritional geometry representation.

SETTING

National Nutrition and Physical Activity Survey 2011-2012 of Australia.

PARTICIPANTS

Respondents (n 5344) aged > 18 years with 1 d of 24-h dietary recall data excluding respondents with missing values and outlier data points and under reporters.

RESULTS

Australian diets rich in UPF were associated with reduced nutritional quality, high greenhouse gas emissions, energy use, and increased employment and income associated with the food supply chains. The environmental and economic impacts associated with the UPF portion of diets become more distinct when the diets are standardised to average protein recommendation.

CONCLUSION

Increased consumption of UPF has socio-economic benefits, but this comes with adverse effects on the environment and public health. Consideration of such trade-offs is important in identifying policy and other mechanisms regarding UPF for establishing healthy and sustainable food systems.

Protein appetite as an integrator in the obesity system: the protein leverage hypothesis

Despite the large volume and extensive range of obesity research, there is substantial disagreement on the causes and effective preventative strategies. We suggest the field will benefit from greater emphasis on integrative approaches that examine how various potential contributors interact, rather than regarding them as competing explanations. We demonstrate the application of nutritional geometry, a multi-nutrient integrative framework developed in the ecological sciences, to obesity research. Such studies have shown that humans, like many other species, regulate protein intake more strongly than other dietary components, and consequently if dietary protein is diluted there is a compensatory increase in food intake-a process called protein leverage. The protein leverage hypothesis (PLH) proposes that the dilution of protein in modern food supplies by fat and carbohydrate-rich highly processed foods has resulted in increased energy intake through protein leverage. We present evidence for the PLH from a variety of sources (mechanistic, experimental and observational), and show that this mechanism is compatible with many other findings and theories in obesity research. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

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.

Environmental impacts and diet quality of popular diet models compared to Turkey's national nutrition guidelines

AIMS

This study aimed to compare the environmental impacts and diet qualities of popular diet models with the recommendations of the Turkish national dietary guidelines.

METHODS

Seven-day isocaloric (8368 kJ) diet models were created taking into account the Mediterranean, Atkins (20/40/100), Ornish, Zone diets, and Turkey Dietary Guidelines-2015 recommendations with different food and nutrient contents. Water footprints were evaluated using the global water footprint standards. Greenhouse gas emissions were evaluated using carbon footprint factors compiled as a result of meta-analyses of life cycle analysis studies in the literature. In addition, the quality of diets was evaluated with the Diet Quality Index-International.

RESULTS

Atkins20 diet model had the most harmful environmental impact (greenhouse gas emissions 8.74 kg CO₂ -eq/per/day and total water footprint 7731 L/per/day), whereas Ornish and Mediterranean diet models (greenhouse gas emissions 2.2/3.07 kg CO₂ -eq/per/day and total water footprints 3184/3675 L/per/day, respectively) had less harmful environmental impact. The highest Diet Quality Index-International score was in the Ornish diet model while the lowest Diet Quality Index-International was in the Atkins20 diet model.

CONCLUSION

Ornish and Mediterranean diet models had less harmful environmental impacts, which contributed to sustainable nutrition. The importance of diet quality and environmental impacts should be kept in mind when evaluating diet models to ensure sustainable nutrition.