An unbalanced diet is bad for your health, but many people have a lack of variety on their plates, especially in poorer countries. This is true in particular for small-farm households, which make up the majority of the malnourished population worldwide. One possible solution to this problem is for these farmers to grow as many different foods as possible for their own consumption. But how effective is this measure, and are there possibly better alternatives?

To answer this question, researchers at the University of Bonn unearthed a comprehensive treasure trove of data. They analyzed surveys of almost 90,000 households in Africa, most of whom were smallholders. The data was collected between 2008 and 2022 in Ethiopia, Malawi, Niger, Nigeria, Tanzania and Uganda. “Among other things, the surveys provided insights into the number of crops the farmers cultivated and the number of animal species they kept,” explains Prof. Dr. Matin Qaim from the Center for Development Research (ZEF) at the University of Bonn. “In addition, the data contained information on the types of food being consumed in each household.”

Greater diversity on farmer’s fields only has a minor effect

The analysis demonstrated that farmers who produced a more diverse range of crops and animals on their farms did indeed have a more balanced diet as a result. “However, this only had a small effect,” says ZEF researcher Dr. Thanh Tung Nguyen, who carried out the study together with Qaim. “Small-scale agricultural production in Africa tends to be highly diverse anyway. Ensuring good access to local and regional markets is more important than further improving the diversity on every single farm. These markets not only allow farmers to sell their surplus food but also enable them to purchase those foods that they are lacking.”

Indeed, an analysis of the foods consumed by farm households showed that markets are in most cases already more important today for a healthy diet than the farmer’s own food production. On average, own production accounted for only around one third of the foods consumed in the farm households analyzed. The nearer the households were to a local market, the more their diets were enriched with purchased foods. This was true for all six of the countries covered by the research. “The study showed that access to local and regional markets is vitally important for a good quality diet,” emphasizes Nguyen. However, there is still a lack of suitable infrastructure in many areas. The roads to the market are often so bad that the journey takes a long time and some of the products spoil or get damaged on the way.

Diversity in the region is more important than diversity on every single field

The researchers recommend that the focus should not only be placed on improving diversity on farmer’s fields but above all on improving infrastructure and thus giving people better access to markets. If the range of products grown by an individual farmer is too diverse, this could even be disadvantageous because each crop has its own needs and requires special expertise. “It is better to focus on those crops that flourish particularly well in the local conditions and then sell any surplus food,” explains Nguyen. At the same time, it definitely makes sense to diversify the crops to a certain extent both from an environmental perspective and to reduce the risks for farmers.

“However, it is certainly not necessary for every small farm to grow all of the products they need for a healthy diet themselves,” says Matin Qaim, who is also a member of the transdisciplinary research area (TRA) “Sustainable Futures” and the PhenoRob Cluster of Excellence. “It is sufficient when a large enough range of foods is produced across the region as a whole because then local households can purchase food diversity at markets.” Trading food in this way enables a division of labor and is thus not only an important tool for improving people’s diets but also helps to promote economic development overall.