Plant-based dietary transitions shift global food production from large to small farms

The way we eat is changing. For decades, scientists and health organizations have agreed that shifting away from heavy meat consumption toward diets rich in plants is one of the most effective ways to protect the environment and improve human health. This idea is not just about what ends up on a dinner plate; it is about the entire machinery of global agriculture that grows, harvests, and ships our food. When people eat less meat and more beans, fruits, and vegetables, the demand for certain crops rises while demand for others falls. This creates a ripple effect that travels through the global food system, altering which fields are planted, which countries export what, and, crucially, who does the farming.

For a long time, researchers have studied these dietary shifts by looking at the total amount of food produced, treating all farms as if they were the same. They calculated how many tons of wheat or soy would be needed in 2050, but they did not ask whether those tons would come from a small family plot or a massive industrial operation. This gap in understanding matters because small farms and large farms play very different roles in the world. Small farms, often run by families with less than five hectares of land, are the backbone of food production in many parts of the world, especially for diverse crops like vegetables and pulses. Large farms, often exceeding fifty hectares, tend to dominate the production of grains and oilseeds used to feed livestock. If we do not understand how a shift to plant-based diets affects these different types of farmers, we risk creating policies that help the environment while accidentally hurting the livelihoods of the people who grow our food.

A team of researchers from Leiden University and the University of Oxford has now filled this gap. They built a detailed computer model that tracks not just how much food is grown, but who grows it. By combining data on the size of farms around the world with projections of how diets might change between now and 2050, they mapped out exactly how the burden of feeding the planet would shift. Their work moves beyond simple totals to reveal a complex story of expansion and contraction across different regions and farm sizes. The results suggest that while small farmers will continue to produce the majority of the world's crops, the specific types of food they grow and the trade routes they rely on will change dramatically depending on how quickly the world adopts plant-rich diets.

The researchers started by creating five different possible futures for human diets. One scenario, called "business as usual," assumes that current eating habits continue to evolve slowly without major changes. The other four scenarios represent significant shifts toward plant-based eating: a flexitarian diet with reduced meat, a pescatarian diet with fish but no other meat, a vegetarian diet, and a strict vegan diet. These scenarios were not just about changing the menu; they were projected to reach full adoption by the year 2050. The team then used a sophisticated economic model to calculate how much of each crop would be needed to feed the global population under these different diets, accounting for how much food is used for human consumption versus animal feed. They also factored in how climate change and technology might affect crop yields over the coming decades.

Once they knew how much food would be needed, the researchers applied a crucial layer of detail: they assigned that food to specific farm sizes. They divided the world's farms into three categories: small (less than five hectares), medium (five to fifty hectares), and large (more than fifty hectares). Using existing global data on where different crops are grown and by whom, they allocated the future production needs to these groups. They did this for every country and for every type of crop, from rice and wheat to soybeans and nuts. They also tracked how food moves between countries, calculating which types of farms are responsible for the exports that end up on tables in other parts of the world. This allowed them to see not just who grows the food, but who supplies the global market.

The findings reveal a clear and significant shift in the global agricultural landscape. Under a business-as-usual scenario, total food production is expected to grow by about 23 percent by 2050. However, under the plant-rich scenarios, the total volume of food needed is much lower, growing by only 6 to 13 percent. This is because plant-based diets generally require less land and resources than meat-heavy diets. But the distribution of this growth is not even. In the business-as-usual world, large farms are expected to increase their production significantly. In contrast, under plant-rich diets, the production growth falls almost entirely on small and medium-sized farms. Large farms, particularly those in the Americas that currently grow massive amounts of corn and soy for animal feed, are projected to see their production volumes decline.

The study highlights that small-scale farmers will remain the dominant force in global food production, regardless of the diet chosen. In 2020, small farms produced about 53 percent of the world's crops. By 2050, this share is expected to rise slightly to between 55 and 58 percent across all scenarios. This means that small farmers will continue to provide the bulk of the world's food. However, the nature of their work will change. In regions like East Asia and the Pacific, South Asia, and Sub-Saharan Africa, small farmers will be responsible for a massive expansion in the production of legumes, nuts, fruits, and vegetables. These are the crops that become more important when people eat less meat. Meanwhile, large-scale producers in the Americas, who currently dominate the production of feed grains, will face a contraction in demand as the need for animal feed drops.

The impact of these changes extends beyond the fields and into the global trade networks that connect farmers to consumers. Currently, large farms dominate international food trade, accounting for about 58 percent of the volume of crops traded between countries. The researchers found that this dominance will shrink as diets change. By 2050, under plant-rich diets, the share of global trade coming from large farms is projected to fall to between 41 and 48 percent. Conversely, the share of trade handled by small farms will rise from 30 percent to between 34 and 38 percent. This shift happens because the crops that are traded most under plant-based diets—such as fruits, vegetables, and legumes—are typically grown by smallholders in developing nations. As countries shift their diets, they will increasingly rely on imports from these small-scale producers, altering the flow of goods across the world.

The study also looked at how these changes play out in specific regions. In East Asia, South Asia, and Sub-Saharan Africa, small farmers will see the largest increases in production volumes for fruits, vegetables, and nuts. This is consistent with the current reality in these regions, where smallholders are already the primary growers of these diverse crops. In contrast, large-scale grain producers in North America and large-scale soybean producers in Latin America will see their production shrink under plant-rich diets, as the demand for feed grains declines. The researchers noted that these shifts are not just about total volume; they represent a fundamental restructuring of who supplies the world. For example, under a moderate shift to a flexitarian diet, trade flows of small-farm crops like sugarcane and cassava within East Asia and between Africa and Asia are expected to expand significantly.

The researchers were careful to note that their work is a simulation based on specific assumptions. They assumed that the structural factors determining which farms grow which crops—such as soil quality, labor availability, and mechanization potential—would remain relatively stable over time. They did not model individual farmers switching crops or changing their business models, but rather looked at how the aggregate production of different farm sizes would adjust to meet new demand. They also considered two possibilities for how farm sizes might change over time: one where the distribution of farm sizes stays the same, and another where farms gradually consolidate into larger units or fragment into smaller ones. Even with these different assumptions, the core finding remained the same: plant-rich diets shift the burden of production growth toward smaller farms and reduce the role of large-scale feed-crop producers.

The implications of these findings are significant for policymakers and agricultural leaders. The study suggests that a transition to sustainable diets cannot be managed by looking at food production as a single, uniform block. The costs and benefits of this transition are distributed unevenly across different types of farmers. Small farmers in developing regions will be called upon to produce more of the specific crops that a plant-based world needs, which could offer new economic opportunities but also requires support in the form of better access to credit, seeds, and markets. At the same time, large-scale farmers in the Americas will need to adapt to a shrinking market for feed crops, potentially repurposing their land for other uses. The researchers argue that ignoring these differences could lead to unintended consequences, such as undermining the livelihoods of smallholders or failing to support the farmers who are essential to the transition.

Ultimately, this research provides a clearer picture of the human landscape behind our food. It shows that moving toward a plant-based future is not just a matter of changing what we eat, but of reshaping the global network of farmers who grow our food. The transition will likely strengthen the role of small-scale producers in many parts of the world while reducing the dominance of large-scale industrial feed production. By understanding these dynamics, society can better prepare for a future where the food system is not only more sustainable for the planet but also more equitable for the diverse array of farmers who make it possible. The study does not predict the future with certainty, but it offers a detailed map of the likely terrain, showing where the paths of different farmers will diverge and converge in the decades to come.