A global shift toward plant-rich diets could significantly improve human health and the environment, according to a growing body of research. Such dietary changes, characterized by an increase in the consumption of fruits, vegetables, nuts, and legumes, while reducing meat intake, have been linked to a lower risk of chronic diseases and a substantial reduction in the environmental footprint of the food system. This transition is seen by many experts as an essential step in addressing the interconnected crises of climate change, biodiversity loss, and public health.
A landmark report from the EAT-Lancet Commission outlines a “Planetary Health Diet” (PHD) that aims to provide healthy food for a global population expected to reach 9.6 billion by 2050, while simultaneously slashing food-related greenhouse gas emissions. The commission, comprised of leading international experts, warns that current food production and consumption habits are a major threat to both human and planetary health. Adopting the PHD worldwide could prevent approximately 15 million premature deaths annually and cut the risk of early death by 27%. The diet is designed to be flexible and adaptable to local cultures and tastes, with the primary emphasis on whole grains, fruits, vegetables, nuts, and legumes, with moderate inclusion of dairy, fish, and poultry, and minimal red and processed meat.
A Prescription for Personal Health
The health benefits of a plant-rich diet are numerous and well-documented. Research indicates that such diets can play a significant role in preventing and managing a range of non-communicable diseases. Evidence from both cohort studies and randomized-controlled trials suggests beneficial effects on weight control, cardiovascular health, and the prevention and treatment of diabetes. The PHD, for instance, has been associated with a significant reduction in the risk of cardiovascular disease, type 2 diabetes, cancer, and neurodegenerative conditions.
The diet’s positive health outcomes are attributed to its emphasis on nutrient-dense foods. The PHD recommends at least five portions of fruits and vegetables, three to four portions of whole grains, and one portion each of nuts and legumes daily. It also suggests moderate consumption of dairy (one serving per day), eggs (three to four per week), chicken and fish (two portions of each per week), and a maximum of one portion of red meat per week. This dietary pattern provides a rich supply of vitamins, minerals, and fiber, while limiting the intake of saturated fats and processed foods, which are often linked to poor health outcomes.
Environmental Dividends of Dietary Change
The global food system is a primary driver of environmental degradation, contributing to a third of all greenhouse gas emissions and being the largest cause of wildlife destruction, deforestation, and water pollution. A transition to plant-rich diets offers a powerful solution to mitigate these impacts. Studies have shown that reducing the consumption of meat and other animal products leads to a significant decrease in environmental pressures. The EAT-Lancet Commission’s report suggests that widespread adoption of the PHD could cut food-related climate emissions by half by 2050.
The environmental benefits extend beyond emissions reductions. Research has found that plant-based diets can reduce land and water use by 28% and 18%, respectively. A study from Harvard University further detailed these benefits, showing that healthy plant-based diets have lower greenhouse gas emissions and require less cropland, irrigation water, and nitrogenous fertilizer compared to diets high in animal-based foods. The study also highlighted that not all plant-based diets are equal in their environmental benefits, with those centered on whole foods being more sustainable than those high in refined grains and sugary drinks.
Global Disparities and the Path Forward
Current dietary patterns vary significantly across the globe, with notable overconsumption of red meat in wealthier nations. In the United States and Canada, for example, people consume more than seven times the amount of red meat recommended by the PHD. This overconsumption is a major contributor to both negative health outcomes and environmental strain. In contrast, some regions, such as sub-Saharan Africa, have diets heavily reliant on starchy foods, and a modest increase in the consumption of chicken, dairy, and eggs could be beneficial for health.
Addressing these disparities is a key component of the proposed dietary transition. The EAT-Lancet Commission’s report emphasizes that the wealthiest 30% of the world’s population are responsible for approximately 70% of the environmental pressures from the food system. A more equitable distribution of food resources and a global shift toward the PHD could help to alleviate this imbalance, ensuring that everyone has access to a healthy and sustainable diet.
Policy and Individual Action
Governmental and Institutional Roles
Experts recommend a range of interventions and policy changes to facilitate the global dietary shift. These include updating national food-based dietary guidelines to incorporate environmental sustainability, a point echoed by researchers at Harvard. Governments can also play a role in promoting the availability and affordability of healthy, plant-based foods, as well as supporting farmers in transitioning to more sustainable agricultural practices, such as regenerative agriculture.
The Power of Consumer Choice
While policy changes are crucial, individual choices also have a significant impact. The flexibility of the PHD allows it to be adapted to individual preferences and cultural contexts, making it an accessible option for many. By choosing to consume more plant-based foods and reduce their intake of animal products, individuals can contribute to a healthier planet and a healthier future for themselves and for generations to come. The evidence is clear: transforming the food system is not just a possibility, but a necessity for a sustainable and equitable world.