Exploring tradeoffs among diet quality and environmental impacts in self-selected diets: a population-based study.

PURPOSE: Proposed sustainable diets often deviate dramatically from currently consumed diets, excluding or drastically reducing entire food groups. Moreover, their environmental sustainability tends to be measured only in terms of greenhouse gases emissions. The aim of this study was to overcome these limitations and identify a cluster of already adopted, relatively healthy diets with substantially lower environmental impacts than the average diet. We also aimed to estimate the reduction in multiple environmental impacts that could be achieved by shifting to this diet cluster and highlight possible tradeoffs among environmental impacts. METHODS: The diet clusters were identified by applying energy-adjusted multiple factor analysis and hierarchical clustering to the dietary data of the National FinHealth 2017 Study (n = 5125) harmonized with life cycle assessment data on food products from Agribalyse 3.0 and Agri-Footprint using nutrient intakes and global warming potential, land use, and eutrophication of marine and freshwater systems as the active variables. RESULTS: We identified five diet clusters, none of which had the highest overall diet quality and lowest impact for all four environmental indicators. One cluster, including twenty percent of the individuals in the sample was identified as a "best compromise" diet with the highest diet quality and the second lowest environmental impacts of all clusters, except for freshwater eutrophication. The cluster did not exclude any food groups, but included more fruits, vegetables, and fish and less of all other animal-source foods than average. Shifting to this cluster diet could raise diet quality while achieving significant reductions in most but not all environmental impacts. CONCLUSION: There are tradeoffs among the environmental impacts of diets. Thus, future dietary analyses should consider multiple sustainability indicators simultaneously. Cluster analysis is a useful tool to help design tailored, socio-culturally acceptable dietary transition paths towards high diet quality and lower environmental impact.

Sustainability benefits of transitioning from current diets to plant-based alternatives or whole-food diets in Sweden.

Plant-based alternatives (PBAs) are increasingly becoming part of diets. Here, we investigate the environmental, nutritional, and economic implications of replacing animal-source foods (ASFs) with PBAs or whole foods (WFs) in the Swedish diet. Utilising two functional units (mass and energy), we model vegan, vegetarian, and flexitarian scenarios, each based on PBAs or WFs. Our results demonstrate that PBA-rich diets substantially reduce greenhouse gas emissions (30-52%), land use (20-45%), and freshwater use (14-27%), with the vegan diet showing the highest reduction potential. We observe comparable environmental benefits when ASFs are replaced with WFs, underscoring the need to reduce ASF consumption. PBA scenarios meet most Nordic Nutrition Recommendations, except for vitamin B12, vitamin D and selenium, while enhancing iron, magnesium, folate, and fibre supply and decreasing saturated fat. Daily food expenditure slightly increases in the PBA scenarios (3-5%) and decreases in the WF scenarios (4-17%), with PBA diets being 10-20% more expensive than WF diets. Here we show, that replacing ASFs with PBAs can reduce the environmental impact of current Swedish diets while meeting most nutritional recommendations, but slightly increases food expenditure. We recommend prioritising ASF reduction and diversifying WFs and healthier PBAs to accommodate diverse consumer preferences during dietary transitions.

Environmental and nutritional Life Cycle Assessment of novel foods in meals as transformative food for the future.

Sustainable diets are key for mitigating further anthropogenic climate change and meeting future health and sustainability goals globally. Given that current diets need to change significantly, novel/future foods (e.g., insect meal, cultured meat, microalgae, mycoprotein) present options for protein alternatives in future diets with lower total environmental impacts than animal source foods. Comparisons at the more concrete meal level would help consumers better understand the scale of environmental impacts of single meals and substitutability of animal sourced foods with novel foods. Our aim was to compare the environmental impacts of meals including novel/future foods with those of vegan and omnivore meals. We compiled a database on environmental impacts and nutrient composition of novel/future foods and modeled the impacts of calorically similar meals. Additionally, we applied two nutritional Life Cycle Assessment (nLCA) methods to compare the meals in terms of nutritional content and environmental impacts in one index. All meals with novel/future foods had up to 88 % less Global Warming Potential, 83 % less land use, 87 % less scarcity-weighted water use, 95 % less freshwater eutrophication, 78 % less marine eutrophication, and 92 % less terrestrial acidification impacts than similar meals with animal source foods, while still offering the same nutritional value as vegan and omnivore meals. The nLCA indices of most novel/future food meals are similar to protein-rich plant-based alternative meals and show fewer environmental impacts in terms of nutrient richness than most animal source meals. Substituting animal source foods with certain novel/future foods may provide for nutritious meals with substantial environmental benefits for sustainably transforming future food systems.

Incorporation of novel foods in European diets can reduce global warming potential, water use and land use by over 80.

Global food systems face the challenge of providing healthy and adequate nutrition through sustainable means, which is exacerbated by climate change and increasing protein demand by the world's growing population. Recent advances in novel food production technologies demonstrate potential solutions for improving the sustainability of food systems. Yet, diet-level comparisons are lacking and are needed to fully understand the environmental impacts of incorporating novel foods in diets. Here we estimate the possible reductions in global warming potential, water use and land use by replacing animal-source foods with novel or plant-based foods in European diets. Using a linear programming model, we optimized omnivore, vegan and novel food diets for minimum environmental impacts with nutrition and feasible consumption constraints. Replacing animal-source foods in current diets with novel foods reduced all environmental impacts by over 80% and still met nutrition and feasible consumption constraints.