Muñoz-Martínez, J., Abejón Elías R., Batlle-Bayer, L., Cussó-Parcerisas, I., Carrillo-Álvarez, E. (2023) Optimizing sustainable, affordable and healthy diets and estimating the impact of plant-based substitutes to milk and meat: A case study in Spain. Journal of Cleaner Production. Volume 424. https://doi.org/10.1016/j.jclepro.2023.138775. (paid access)
Dietitians and public health nutritionists, Health care professionals, Policy makers
How is an environmentally sustainable, affordable, culturally acceptable, and nutritious diet determined in Spain? What is the sustainability of current Food-Based Dietary Guidelines (FBDG)? How much can we rely on plant-based milk and plant-based meat from a sustainability perspective ?
Bottom line for nutrition practice:
- It is paramount to evaluate the sustainability of diets from a holistic and context-based perspective. Our analysis revealed that although the Spanish FBDG have lower Greenhouse Gas emissions (GHGe) than current diets, they are more blue-water demanding and also more expensive due to the high content in plant-based foods.
- We were able to determine a nutritious diet with the lowest environmental impact and lowest cost, but results revealed the need to apply actions at systems level to enable more environmentally respectful production practices, and make healthy foods more affordable.
- Processed plant-based meat alternatives are not required to achieve a sustainable and healthy diet.
- The global food system is failing to appropriately nourish the population and has been identified as a driving force for environmental degradation. Changing current diets to healthier and more sustainable ones is key to decrease the incidence of non-communicable diseases and force changes at the production stage that will release environmental pressure. The determination of such diets is a challenge since it should be context specific, culturally acceptable, affordable, nutritionally adequate, and environmentally friendly.
- Through multiobjective optimization we aimed to determine a sustainable and healthy diet (SHD) in Spain with the minimum cost and environmental impact (assessed through GHGe, land use and blue-water use) that deviate the least from current consumption. Additionally, this research also compares the optimised diet with the Spanish food-based dietary guidelines (FBDG), and explores the potential benefits of reducing animal meat and milk while replacing them with plant-based alternatives. Compared to current consumption, a SHD in Spain can be more nutritious and reduce cost, GHGe, land and blue-water use by 32%, 46%, 27%, and 41%, respectively.
- The Spanish intake displayed the worst nutritional assessment and the highest values for GHGe and land use. The Spanish FBDG showed the highest cost and blue-water usage. Further analysis revealed that plant-based meat alternatives are not necessary to achieve a nutritionally adequate diet at the minimum cost and environmental impact. Shifting to fortified plant-based milk alternatives may add additional environmental benefits.
- This work emphasizes the potentiality of using optimization to determine a SHD and identifies important gaps to be fulfilled in future research.
Details of results:
- Compared to the Spanish intake, a nutritionally adequate sustainable and healthy diet can be 1.61 € cheaper, reduce GHGe by 2.33 kgCO2eq, land use by 1.5 m2, and blue water use by 156 L.
- The Spanish FBDG basket was the most expensive and blue water demanding, mainly explained by the high content of fruits and vegetables.
- The Spanish intake showed the lowest nutritional index and the highest GHG and land footprint due to the high content of animal protein.
Of additional interest:
- Hot Topic Resource Cluster: Animal Proteins & Substitutes (2022 May)
- Learning Module 2: How are Sustainable Food Systems and Diets Relevant to Nutrition and Dietetic Practice?
- Comparative analysis of environmental impacts of agricultural production systems, agricultural input efficiency, and food choice (2017)
- Health and environmental impacts of plant-rich dietary patterns: a US prospective cohort study (2022 Nov)
Conflict of interest/ Funding:
Júlia Muñoz Martínez, firstname.lastname@example.org