What Policies Are Needed to Promote Secure, Climate-Resilient, and Nutritious Diets Worldwide?
Introduction
Long-term climate change and short-term extreme weather events adversely affect food security, diets, and nutrition through complex and interconnected pathways involving food, health, water, and social protection systems. However, it remains challenging to measure the impacts of climate-related dietary malnutrition, particularly among the most vulnerable populations. Nonetheless, emerging evidence indicates that climate change affects both the diversity of diets and access to food. Further exploration is needed to understand the pathways, mechanisms, and driving factors behind these impacts.
The current state of diets
Global dietary patterns have changed significantly over the years, leading to mixed health outcomes. Since 1961, food availability has increased from 2,181 to 2,920 calories per person per day. However, the quality of diets has only seen modest improvement since 1990 (FAO, 2024). Most regions continue to fall short of the recommended intakes for fruits, vegetables, legumes, nuts, and whole grains, while they exceed recommendations for added sugars and sodium. Additionally, the rise of cheaper ultra-processed foods in diets worldwide has contributed to lower diet quality and poorer health outcomes (Lane et al 2024). Furthermore, inadequate diets are estimated to cause approximately 12 million adult deaths each year (Afshin et al., 2019).
From a sustainability perspective, animal-source foods, particularly beef and lamb, are the largest contributors to environmental issues, including greenhouse gas emissions and changes in land use. Between 1961 and 2020, global per capita meat consumption nearly doubled, with the most significant increases observed in rapidly growing economies such as China and Brazil (Fanzo & Miachon, 2023). To mitigate these environmental impacts, the EAT-Lancet Commission recommends diets focused on whole grains, pulses, nuts, legumes, fruits, and vegetables, while minimizing the intake of unprocessed red meat (Willett et al., 2019). These dietary changes are crucial for reducing the environmental burden of the food system and improving nutritional outcomes.
Despite an increase in global food production over the past five decades, approximately 2.8 billion people—equivalent to 40 percent of the world’s population—could not afford a healthy diet in 2020. This represents an increase of 112 million people since 2019, primarily due to rising food prices (FAO, 2024). Barriers to food access include physical proximity to markets, which is especially impactful in low- and middle-income countries, as well as economic affordability; nutritious foods are significantly more expensive than staple items. In regions such as sub-Saharan Africa, animal-sourced foods are cost-prohibitive compared to starchy staples.
Dietary patterns vary greatly worldwide, and many inequities exist regarding the ability to access healthy foods within populations. Within countries and communities, dietary traditions are influenced by culture, geography, and available resources. Some populations consume diets with much higher environmental and climate footprints than others and are beginning to implement changes.
Policies targeting both the supply and demand of food systems
The holistic nature of food systems enables a wide range of innovative policies and programs aimed at providing diets that are healthy for populations and sustainable for the planet (Fanzo et al., 2021; Schneider et al., 2023). For instance, one modeling study indicates that achieving the Paris Agreement climate targets could be feasible if action is taken across various food system activities. These actions include improving food efficiency on farms, increasing crop yields without expanding into biodiverse landscapes, moving towards diet patterns that prioritize sustainability, consuming portions necessary for maintaining a healthy weight, and reducing food loss and waste (Clark et al., 2020). It is important to implement these actions not in isolation but as a unified approach to ensure that food system transformations align with climate change mitigation goals.
Policies and actions addressing both supply and demand can be enacted to make food production, processing, and transportation more sustainable. The EAT-Lancet Commission provides a possible roadmap for diversifying production, reducing greenhouse gas (GHG) emissions, improving soil and water management in agricultural landscapes, minimizing food loss and waste, and encouraging demand for healthier diets (Willett et al., 2019). Other potential solutions include homestead gardening, biofortification, reformulating food products to eliminate unhealthy ingredients, taxing sodas and highly processed foods, implementing front-of-pack labeling to indicate the healthfulness of food products to consumers, establishing national food-based dietary guidelines, and creating food-related safety nets.
Rosenzweig et al. (2020) calculated the total technical and economic potential for mitigating GHG through technology diffusion in both supply-side activities (crop, livestock, and agroforestry) and demand-side dietary changes. On the supply side, technical mitigation provides a potential reduction of 2.3 to 9.6 gigatons of CO2 equivalent per year, while the economic potential ranges from 1.5 to 4.0 gigatons. On the demand side, technical mitigation offers a wider range of 0.7 to 8.0 gigatons per year, with an economic potential of 1.8 to 3.4 gigatons. The authors explored various adaptation and mitigation strategies across food systems, highlighting the synergistic potential and co-benefits of these strategies across multiple outcomes.
There are ways to help guide populations toward healthier and more sustainable food choices, and food environments influence dietary choices and decisions. Choice architecture refers to the design of food environments and retail spaces in a way that makes specific foods more convenient to see, order, and choose. This involves considerations such as pricing, attractiveness of appearance and packaging, and ease of cooking, serving, and consuming. Unfortunately, many food environments currently trigger unhealthy and unsustainable choices. For example, grocery store checkout lines are commonly stocked with highly palatable ultra-processed foods encased in plastic wrapping that are easy to grab and relatively inexpensive. Interventions to improve these detrimental designs include: (1) enhancing the visibility of healthier foods over unhealthy options in markets; (2) reducing the size of plates and trays in cafeterias; (3) ensuring meals can be quickly packaged for takeout; (4) decreasing the portions of unhealthy packaged foods; and (5) increasing sustainable packaging for healthy options.
A key aspect of designing food environments involves nudging, defined as “any aspect of choice architecture that alters people’s behavior in predictable ways without restricting options or significantly changing their economic incentives, such as time or money” (Leonard, 2009). Nudges are subtle methods to influence dietary choices where people live, shop, work, and learn. One emerging nudge is the availability of alternative meats on store shelves. These products mimic the taste, smell, and appearance of meat, requiring little adjustment in terms of palatability or cooking methods. While the health profiles of these foods are questioned due to high processing levels, they could serve as important substitutes for consumers concerned about animal welfare or the environmental impact of their diets (UNEP, 2023).
Challenges
The first challenge emphasizes that although various solutions have been proposed and implemented to address access constraints in local contexts, many have not been scaled effectively enough to create significant, positive impacts. The second challenge involves addressing power imbalances in food policy and politics. Private companies operating at every stage of food supply chains are becoming increasingly concentrated, holding considerable economic and political influence. Some of these companies continue to generate substantial profits, often at the expense of public health and environmental sustainability, resulting in a lack of trust from other stakeholders. This discord threatens the collective momentum necessary to transform the global food system.
The third challenge highlights the need for data to evaluate the performance of food systems, identify effective interventions, and assess any unintended consequences or trade-offs associated with implemented solutions. To tackle these issues, sixty food system experts have created the Food Systems Countdown to 2030 Initiative, which aims to guide and hold both public and private sector decisions accountable. The Countdown reveals that no single region has achieved complete success in its food system. Every region and country have room for improvement, and there are valuable lessons to be learned from one another. Governments must take action to restore balance of power and play a more proactive role in positively guiding food systems. Investment in place-based solutions is crucial for understanding what works, in which context, and for whom (Fanzo et al., 2024).
Conclusion
To achieve the food transformation the global community seeks, we must make food systems resilient to climate change and capable of providing healthy diets for all in an equitable way. This requires stakeholders to change behaviors, take action, and be accountable. However, trade-offs will arise from differing ideologies, national interests, and policy inconsistencies, potentially leading to disagreements (Bene, 2022). Balancing health, environmental, and equity considerations poses challenges for sustainable food systems. Policies targeting social food security and nutrition are expected to have a greater impact on sustainability than those focused solely on environmental or economic aspects. Ultimately, the best interventions will depend on each country’s context, resources, and local policies (Scheider et al., 2025).
Attention should be given to the political and economic aspects of food system reforms, recognizing how these changes affect different groups. Political leaders and agri-food industry players are under growing pressure to address climate change. With eight billion consumers increasingly aware of the links between food systems, health, and global welfare, access to data and awareness of enabling political conditions can empower civil society and the media to advocate for necessary changes.
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