Greenhouse gas emissions in relation to micronutrient intake and implications of energy intake: a comparative analysis of different modeling approaches (2025)

Citation: Stubbendorff, A., Hallström, E., Tomova, G., Borné, Y., Janzi, S., Sonestedt, E., & Ericson, U. (2025). Greenhouse gas emissions in relation to micronutrient intake and implications of energy intake: A comparative analysis of different modeling approaches. The American Journal of Clinical Nutrition, 121(5), 1063–1076. https://doi.org/10.1016/j.ajcnut.2025.02.031 (open access)

Abstract

  • Background – Human diets account for 30% of greenhouse gas emissions (GHGE). Reporting dietary GHGE with or without energy standardization yields different outcomes, often resulting in conflicting conclusions regarding associations with micronutrient intake.
  • Objectives – This study aims to compare methods of reporting dietary GHGE, with and without consideration of energy intake, and their respective associations with micronutrient intake.
  • Methods – Data were sourced from the Malmö Diet and Cancer Study, a cohort involving 25,970 participants. GHGE were estimated based on life cycle assessment data. The study explores different methods of reporting dietary climate impact: GHGE per day, GHGE per 1000 kcal, and with different energy adjustments. Association with micronutrient intake was modeled as daily intake and per 1000 kcal using linear regression models.
  • Results– Diets with higher GHGE per day were associated with a higher daily intake of all 17 examined micronutrients. When energy was included in the model, the results for GHGE per 1000 kcal aligned well with those for GHGE per day. However, using GHGE per 1000 kcal generally showed that higher GHGE were linked to lower daily micronutrient intake. Different methods of adjusting for energy intake yielded estimates with varying directions and magnitudes of associations.
  • Conclusions – This study highlights the implications of energy intake when assessing the impact of dietary GHGE and demonstrates that the choice of GHGE modeling approach might have important consequences for the results and interpretation. The method of choice for modeling dietary GHGE in relation to micronutrient intake needs to be carefully considered in future studies.

The Coolfood (website)

The Coolfood Pledge helps your organization commit to and achieve a science-based target to reduce the climate impact of the food you serve. Organizations serving 2.4 billion meals a year have signed up. Members are guided through a three-step approach: Pledge, Plan, and Promote.

If you are a business looking to reduce the impact of the food you serve, there are two ways you can help make a difference. By taking the Coolfood Pledge or through labeling Coolfood Meals on your menu. 

Join a growing movement to put sustainability on the menu

Nourish Leadership in Health Care (website)

Nourish fosters the transition toward health care systems that are more preventative, equitable, and sustainable. Nourish works with health care organizations, communities, and policy-makers throughout Canada to improve food in health care—one hospital tray at a time. Nourish is changing the way food is served in health care settings — not just for the well-being of the patients, but for the people caring for them; for growers and food producers; for communities; and for the planet we all share.

Guide to Best Practices and Green Criteria for Low-Carbon Food Procurement (March 2025) – Nourish developed this resource as recommendations and advice to address the needs expressed by the Buyers for Climate Action (BCA), a coalition of leading green public buyers, to enable more low-carbon food procurement. The guide outlines key strategies for advancing low-carbon food procurement, which is imperative for the transition to net zero. These practices are gaining momentum in health care and on campuses across the country. Best practices and green criteria are detailed in this guide and can support greater low-carbon food procurement by the public sector and the greening of government operations.

The free “Food is Our Medicine online Action Learning series” is designed to introduce Canada’s health care professionals and leaders to new and different ways of understanding the complex relationships between Indigenous foodways, reconciliation, healing, and health care. You will have opportunities to learn and reflect on (de)colonization, the perspectives, cultures, and foodways of various Indigenous communities, and steps you can take toward honouring Indigenous worldviews in health care. Participation is free, you complete it at your own pace, and the entire course takes approximately 15 hours.

Building a more sustainable food system in Colombia: a role for nutrition professionals (2025)

McCullum-Gomez, C., Castillo Quiroga, Y. M., & Diaz-Beltran, M. (2025). Building a more sustainable food system in Colombia: a role for nutrition professionals. Academia Nutrition and Dietetics, 2(2)

This article describes multiple efforts to facilitate the transition to a more sustainable food system in Colombia, which can contribute to the achievement of climate-, biodiversity-, and health-related goals. These interconnected goals are aligned with Colombia’s plan for sustainable development and food sovereignty, guided by a food systems typology developed by the World Wildlife Fund, Colombia, and through support of the concept known as Buen Vivir.

Public health nutrition professionals can increase food security, build food sovereignty, and facilitate the transition to a more sustainable food system in Colombia through: (1) community food gardening and peri-urban and urban agriculture projects; (2) institutional- and consumer-level food waste reduction and prevention programs; and (3) sustainable menu projects that incorporate indigenous, native, and local foods that facilitate the recovery of food memory. Such projects should be participatory and tailored to meet the needs of stakeholders in the different regions of Colombia.

Planet friendly home-grown school feeding: What does it mean? (Africa, 2024 Jul)

Borelli, T., Nekesa, T., Mbelenga, E., Jumbale, M., Morimoto, Y., Bellanca, R., & Jordan, I. (2023). Planet-friendly home-grown school feeding: What does it mean? World Food Programme. https://www.wfp.org/publications/planet-friendly-home-grown-school-feeding-what-does-it-mean

This research seeks to improve the environmental sustainability of school meals in Sub-Saharan Africa by developing a practical tool to guide Planet Friendly procurement practices and HGSF approaches and support the transition to more sustainable food systems.

School meals present a unique opportunity to tackle the various food system challenges, including the depletion and pollution of natural resources, habitat and biodiversity loss, deforestation, ocean acidification, and climate change while delivering multiple social and economic benefits towards sustainable food systems for healthy diets. Despite these advantages, the approach is challenged by the lack of evaluation tools and metrics that can be used to quantify the level of “planet friendliness” in the different regions where the Home Grown School Feeding approach is applied.

Through evaluation of the current school meal supply chain in Sub-Saharan Africa, this study identifies practices in food production, transport, processing, and storage that may influence the impact of school feeding programs on planetary health. The study initially focuses on three main products supplied to schools by the World Food Program (WFP) – maize, beans, and dark green leafy vegetables – and proposes to focus on general agronomic, food processing, and handling practices.

The assessment undertaken has resulted in an evaluation tool for all of WFP’s farmer-directed procurement processes linked to school feeding. The proposed tool, currently in draft form and yet to be tested, provides information about indicators to be included in food procurement policies and processes for the provision of greener school meals in low- and middle-income countries (LMICs). The tool is intended to simplify the evaluation of current procurement processes and guide future decision-making around school procurement to ensure planetary health considerations are widely adopted to bolster systemic resilience. The tool can serve multiple purposes: as a checklist, a scoring template for refining tenders, a monitoring and evaluation tool, or a foundation for co-creating policies for any school feeding program at the school, local, or national level.

Submitted by Christine McCullum-Gomez, PhD, RDN

What factors influence sustainable and healthy diet consumption? A review and synthesis of literature within the university setting and beyond (2024)

Elliott, P. S., Devine, L. D., Gibney, E. R., & O’Sullivan, A. M. (2024). What factors influence sustainable and healthy diet consumption? A review and synthesis of literature within the university setting and beyond. Nutrition Research, 103, 1-12. https://doi.org/10.1016/j.nutres.2024.03.004

Highlights
• We identified factors that may influence sustainable and healthy diet consumption.
• Using a novel scoring system, these factors were then ranked by priority.
• The scoring system identified high-priority factors to target in future research.
• Most high-priority factors were at the environmental level (e.g., product price).
• These findings can inform the development of future personalized interventions.

Abstract
Globally, typical dietary patterns are neither healthy nor sustainable. Recognizing the key role of dietary change in reducing noncommunicable disease risk and addressing environmental degradation, it is crucial to understand how to shift individuals toward a sustainable and healthy diet (SHD).

In this literature review, we introduced the concept of SHD and outlined the dietary behaviors necessary to transition toward SHD consumption; we reviewed the literature on factors that may influence sustainable (and unsustainable) dietary behaviors in adults; and we developed a novel scoring system to rank factors by priority for targeting in future research. Given the significant potential to promote an SHD transition on the university campus—where factors that may impact dietary behaviors can be targeted at all levels of influence (i.e., individual, interpersonal, environmental, policy)—we narrowed our focus to this setting throughout.

Aided by our novel scoring system, we identified conscious habitual eating, product price, food availability/accessibility, product convenience, self-regulation skills, knowledge of animal ethics/welfare, food promotion, and eating norms as important modifiable factors that may influence university students’ dietary behaviors. When scored without consideration for the university population, these factors were also ranked as the highest priority, as were modified portion sizes.

Our findings offer insight into factors that may warrant attention in future research aimed at promoting SHDs. In particular, the high-priority factors identified from our synthesis of the literature could help guide the development of more personalized dietary behavioral interventions within the university setting and beyond.

School Meal Programs Around the World: Results from the 2024 Global Survey of School Meal Programs: Survey Highlights (2024)

The Global Survey of School Meal Programs was launched in 2019 to gather information about school meal programs in every country in a standardized manner, and it has been repeated every 2-3 years. The survey spans a broad set of topics of relevance to school meals, bringing them together under one umbrella to spotlight their linkages. The 2024 Global Survey of School Meal Programs received a response from 142 country governments, which represents 73% of the 194 countries that were invited to participate in the survey.

School meal programs have the potential to play an important role in food systems transformation. This follows from the aggregate scale of these programs, which reach at least 408.2 million children worldwide and are found in at least 148 countries. It also follows from the programs’ multisectoral nature, with relevance for social protection, education, health and nutrition, agricultural and economic growth, and environmental sustainability. School meal programs touch on each of the key goals of food systems transformation.

Environment and Climate

Sustainability is increasingly prioritized in school meal programs, with countries implementing a variety of initiatives to both limit their environmental vulnerability and reduce their environmental impact. The Global Survey of School Meal Programs captured various indicators of environmental sustainability in school meal programs.

  • A large majority (81%) of school meal programs took some steps to limit food waste. This was generally more common in lower-income settings, where food tends to be less plentiful.
  • A majority (67%) of school meal programs also took some steps to limit package waste. Most commonly, these included the re-use of bags/containers (followed by 57% of programs that took some step to limit package waste) and the recycling of packaging materials.
  • Approximately 58% of school meal programs relied on wood stoves or charcoal stoves for food preparation, and among these, 78.5% took some steps to reduce the use of firewood/charcoal as fuel. Toward this end, the most common step taken was the use of fuel efficient (energy efficient) stoves.
  • As part of the food system, school meal programs are both affected by, and a driver of, climate change. Nevertheless, just 38% of programs targeted foods that were considered to be “climate friendly”.
  • On the other hand, a large majority (79%) of programs took some steps to reduce the distance traveled by food from the site of production to consumption (i.e., the food miles/kilometers). Across regions, this emphasis on local procurement was most common in Sub-Saharan Africa, where 89% of programs aimed to reduce the distance traveled by food.

Greener Allied Health Professional Hub: Food & Nutrition (NHS, UK)

The UK National Health Service (NHS) has the third largest clinical workforce in the NHS. Allied Health Professionals (AHPs) play an important role in Delivering a Net Zero NHS, which is the overarching framework.

The “Greener Allied Health Professional (AHP) Hub” aims to provide:

  • Information on the importance of environmental sustainability for both population health and the health of the environment to provide clear actionable steps which AHPs can take to improve their own environmental sustainability.
  • Examples of the ways in which AHPs are already doing things which improve environmental sustainability to include ‘what good looks like’ for individual AHPs and their teams as well as wider examples demonstrating how AHPs can lead this work in their organisations.
  • Suggestions of how AHPs can contribute in relation to environmentally sustainable practice, digital, food and diet, use of equipment and public health and prevention.

Food & Nutrition is one of the focus areas for the Greener AHP Hub. As a food and nutrition professional, this NHS resource outlines key areas where you can make a difference in reducing the carbon footprint of healthcare food systems. It highlights your role in reducing food waste through optimizing mealtime support, promoting best practices, and utilizing technology for ordering and monitoring.

By advocating for healthy, low-carbon diets and minimizing packaging waste, you can address the broader impacts of food systems. This resource will help you implement strategies such as conducting waste audits, supporting patients in adopting better eating habits, and promoting the importance of nutrition and hydration among food service staff. Ultimately, this page equips you to link food, health, and climate change initiatives within the NHS, driving sustainable practices and better patient outcomes.

An example is the “Sustainability in Healthcare: Mildmay’s Low-Carbon Menu Transforms Patient Care“. Mildmay Hospital’s dietetics and catering teams, in collaboration with the NHS and dietetics students, developed a low-carbon menu tailored to vulnerable patients using recipes from the NHS England recipe bank. After iterative development and feedback, the winter menu achieved an 18% carbon footprint reduction and minimized food waste to 10% of portions served, while patient input led to further improvements like diverse recipes and a weekly cooked breakfast option for summer.



Drivers of the food system based on food sovereignty domains: an integrative systematic literature review (2024)

Rivera, I., Díaz de León, D., & Pérez-Salazar, M. del R. (2024). Drivers of the food system based on food sovereignty domains: An integrative systematic literature review. Frontiers in Sustainable Food Systems, 8. https://doi.org/10.3389/fsufs.2024.1450321

Abstract

Food sovereignty, as defined by the comprehensive definition offered in the 2007 Nyéléni Forum, encompasses essential action lines for transforming a food system based on food sovereignty principles. Understanding how current food system initiatives align with these principles is essential for identifying the necessary processes of change to drive this transformation. This study aimed to consolidate the contributions of advancements in food sovereignty to the existing literature.

A systematic literature review was conducted to achieve this, analyzing 250 papers published between 2008 and 2023. The focus was on the research methods employed by the authors, food initiatives within the domains of food sovereignty, and the key drivers of a food system rooted in food sovereignty principles.

The findings revealed that approximately 36% of the studies utilized interviews, surveys, and questionnaires for data collection, while 34% concentrated on targeted fieldwork through case studies. Around 19% of the studies involved in-depth interaction with specific groups, and just under 10% employed document analysis methods. The most extensively discussed domain was the use of agroecological management practices for food production, followed by the valuation of traditional knowledge, the promotion of social justice and equity, self-determination through the transformation of economic and political institutions, and the localization of food production and consumption.

The food initiatives outlined overarching goals within each domain of food sovereignty, with three common goals identified across these domains: food security and consumption, environmental stewardship, and crisis preparedness. Furthermore, 29 drivers of a food system based on the domains of food sovereignty were identified, encompassing networks and a holistic approach present in all 5 domains. The study also highlights the implications for supporters of food sovereignty within the context of the identified goals of the food initiatives.

Choice architecture promotes sustainable choices in online food-delivery apps (2024 Oct)

Lohmann PM, Gsottbauer E, Farrington J, Human S, Reisch LA. Choice architecture promotes sustainable choices in online food-delivery apps. PNAS Nexus. 2024 Sep 19;3(10):pgae422. doi: 10.1093/pnasnexus/pgae422. PMID: 39372540; PMCID: PMC11450623. (open access)

Abstract

Greenhouse gas emissions from the food system constitute about one-third of the global total, hence mitigation in this sphere of human activity is a vital goal for research and policy.

This study empirically tests the effectiveness of different interventions to reduce the carbon footprint of food choices made on food-delivery apps, using an incentive-compatible online randomized controlled trial with 4,008 participants. The experiment utilized an interactive web platform that mimics popular online food-delivery platforms (such as Just Eat) and included three treatment conditions: a sign-posted meat tax, a carbon-footprint label, and a choice-architecture intervention that changed the order of the menu so that the lowest carbon-impact restaurants and dishes were presented first.

Results show that only the choice-architecture nudge significantly reduced the average meal carbon footprint—by 0.3 kg/CO2e per order (12%), driven by a 5.6 percentage point (13%) reduction in high-carbon meal choices. Moreover, we find evidence of significant health and well-being co-benefits. Menu repositioning resulted in the average meal order having greater nutritional value and fewer calories, whilst significantly increasing self-reported satisfaction with the meal choice.

Simple back-of-the-envelope calculations suggest that menu repositioning would be a highly cost-effective policy instrument if implemented at scale, with the return on investment expected to be in the range of £1.28 to £3.85 per metric ton of avoided CO2 emissions, depending on implementation costs.