New study in Nature – Sustainable Agriculture


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We show how forest regrowth in Nigeria has affected people’s dietary quality. We do so by combining a new map on forest regrowth with food consumption panel data from over 1100 households.

We use a a combination of regression and weighting analyses to generate quasi-experimental quantitative estimates of the impacts of forest regrowth on people’s food intake. We find that people living in areas where forest regrowth has occurred have a higher intake of fruits and vegetables and thus higher dietary diversity.

New study in Nature Food

We examined monthly variation in women’s wild food consumption in two districts in India. After identifying that women most frequently consumed foods from forests and common lands in June and July, we estimated the contribution of wild food consumption to dietary diversity (a measure of diet quality), in these months. We used matching — a rigorous, quasi-experimental method — and regression analysis to isolate the causal relationship between wild food consumption and dietary diversity. Women who consumed wild foods were matched to women who did not consume wild foods on key socioeconomic, dietary and forest-level covariates – to ensure that differences in dietary diversity could be attributed to wild food consumption.

We found that women who consumed wild foods had higher average dietary diversity. In June, those women consumed an extra 0.34 food groups and, in July, they consumed an extra 0.30 food groups compared to women who did not consume wild foods.

My little guide to wild foods

Research on how to improve food and nutrition security has the potential to make real-life contributions for local communities suffering from nutrient deficiencies. Yet, most research remains inaccessible to people who could benefit from it. To elevate the impacts of research beyond a scientific paper, we developed and distributed a children’s book on wild foods in Malawi and Tanzania.

The book contents are based on results obtained from data on wild food consumption in Malawi and Tanzania, collected by PhD students Emilie Vansant and Rasmus Skov Olesen. Together they surveyed more than 1000 households across 16 sites in the two countries. The book is designed to educate young children in rural Africa about how wild foods from the forest can contribute to healthy diets. The illustrations were developed in collaboration with graphic facilitator Mette Jeppesen and highlight the importance of consuming foods rich in micronutrients, such as Vitamin A. To better acquaint children with their surrounding landscape, it features common tree species (e.g. wild custard apple, wild java plum) and green leafy plants (e.g. wild cow peas, black jack) and their various functions, including providing nutrient-rich fruits and vegetables.

We traveled to Tanzania and Malawi in March 2023 and distributed the book to ~1500 children across 16 schools through interactive workshops designed to engage students with the book’s contents. When distributing the book to school children, the book was first read out loud to the children with the help of local research assistants. Graphic Facilitator Mette sketched a human body and explained how eating nutritious fruits and vegetables can be good for your eyesight, strength and health. The workshops finished with a drawing activity, where the children were invited to pick certain leaves and fruits to draw together on large sheets of paper. These collective ‘nutritious landscape drawings’ were then left to decorate the classrooms.

New study published in One Earth

Achieving food and nutrition security for the world’s population while at the same time reversing and minimizing damage to the natural environment is a grand societal challenge. A growing body of evidence has shown that access to forests can support food security in some settings, but the linkages between forests and people’s diets are not well understood. The goal of this review is to provide an overview of the explanations behind observed associations between forests and food and nutrition security. We found that 77% of publications show that forests contribute positively to food and nutrition security. The two main explanations are (1) the direct provision of forest foods and (2) indirect effects from forest-based ecosystem services on surrounding agriculture. Our findings suggest that it is pertinent to rethink the dichotomy between agriculture and nature and move toward more integrated nutrition-sensitive landscapes.

Systematic Literature Review: Tree-based farming systems can be a win-win for people and nature

Fruit and timber trees scattered within maize fields in Mulanje District, Malawi (photo credit: Emilie Vansant)

A new paper was published in People & Nature by Emilie Vansant in collaboration with a team of scientists at CIFOR-ICRAF. The study reviews literature linking tree-based farming systems and dietary quality in low- and middle-income countries (LMICs). The synthesis of 36 studies finds:

  1. Maintaining trees in and around farmland – and using these trees for both the direct provision of foods and as a source of income – can serve as a key strategy for households to diversify food consumption and improve dietary quality.
  2. How much a tree-based farming system can influence diets is dependent on policies and institutions at the national scale, bioclimatic and geographical factors at the landscape scale, as well as socioeconomic factors at both the landscape and household levels.
  3. Indigenous populations practicing traditional forms of tree-based farming (which are often diverse systems integrated with wild landscapes) seem to maintain high levels of dietary quality through sourcing food from both wild and cultivated areas

The existing evidence, though limited, points at important knowledge gaps – namely the lack of a typology of tree-based farming systems to facilitate objective comparisons across cultural and geographical contexts. Additionally, there is a paucity of research that explicitly examines the role of non-forest trees in influencing dietary quality. By recognizing the potential of trees to contribute to positive nutritional outcomes in rural communities, this study supports the development of nutritionally-sensitive landscapes in LMICs.

Promotion of the article in CIFOR’s Forest News blog:

Read the full article here.

A global shift towards more plant-based diets is recommended, but is a uniform approach the best solution for countries with different nutritional and socio-economic challenges?

Our new commentary in One Earth argues that a “one-size fits all” approach to achieving a global shift towards more plant-based diets is unlikely to be successful given the different nutritional and livelihood challenges facing different world regions

Partnership with ICRAF-CIFOR and the Nutri-Scapes Platform

Emilie Vansant, a PhD Fellow on the FORESTDIET project, was recently awarded a small grant to contribute to the recently-established Nutri-Scapes Transformative Partnership platform, a joint initiative by the Center for International Forestry Research (CIFOR) and World Agroforestry (ICRAF). The platform aims to foster the development of nutrition-centered landscapes that can simultaneously support food security, livelihoods and conserve biodiversity.

In line with Nutri-Scapes’ objectives, Emilie is examining existing empirical research on the linkages between different classifications of tree-based agricultural systems and dietary quality in low- and middle-income countries (LMICs). Her planned synthesis will add to existing knowledge on forest-diet linkages and agrobiodiversity-diet linkages by focusing on agricultural systems that utilize single trees, tree crops, and/or forest cover. Classifying farming systems by tree-cover amount, configuration, and level of integration could lend valuable insight into how tree-based farming can provide direct and indirect benefits to the diets of small-holder farmers. Using the relationships between forests and diets as a point of departure, her narrow scope will permit a thorough examination of these complex mechanistic pathways in an agricultural context and allow for comparison across a gradient from single trees towards dense, forest-based farming systems.

Farming with trees in Sarawak, Malaysia (personal photo, 2018)

“Food quality could be more problematic than food quantity for sub-Saharan countries over the coming decades”

A summary of my PhD findings, by Charlotte Hall

Providing the global population with sufficient and nutritious food, while also trying to minimise and reverse damage to the natural environment, is a major societal challenge. Nowhere is this challenge greater than in sub-Saharan Africa (SSA) where one in four people are currently undernourished, and micronutrient deficiencies are widespread. The results of my PhD findings suggest that food supply quality (in terms of micronutrient provision) could be more problematic over the coming decades than food supply quantity (in terms of dietary energy provision) in SSA, using Malawi as a case study. Using a novel modelling framework (FEEDME), supplies of energy, protein, iron, zinc and vitamin A were assessed under a range of future climatic and socio-economic scenarios. In all future scenarios, supplies of energy and protein were adequate, whereas supplies of the three micronutrients were inadequate to meet population-level requirements (with the exception of zinc in a ‘best-case’ future scenario) (see Figure 1). These results are novel as the majority of studies to date have focused on impacts on yields of staple crops and the resulting impact on undernourishment prevalence. The suggestion that nutrient supply may be more problematic in the future than energy supply highlights the need to move beyond the traditional focus on the production of staple crops towards a more holistic view of nutrition security whereby dietary diversity and consumption of micronutrient-dense foods are promoted. Indeed, until very recently, Malawian households were considered to be food secure if they had adequate access to maize with little to no emphasis on dietary diversity. This situation is reflected in (and exacerbated by) national development agendas whereby food security is a key priority for agricultural policies, but nutritional issues (such as stunting and wasting) are considered a health issue. This lack of nutritional consideration within agricultural systems can be considered one of the main causes of food insecurity and malnutrition in today’s society. It is essential that agricultural and nutrition sectors work together in order to form food security strategies that tackle not only undernourishment, but micronutrient deficiencies and their associated health consequences.

In an attempt to explore solutions and adaptation options for Malawi, my PhD research also examined the linkages between land use and dietary quality. The results showed a positive relationship between households located in more forested areas and vitamin A adequacy. Indeed, households who reported consuming wild foods had a 54% higher intake of vitamin A than households who did not consume these foods ( These results are supportive of a wider literature which shows forests can have a multitude of benefits for human health. The implications of these results are strongly linked to the earlier findings surrounding dietary quality, as the focus on increasing yields of staple crops via agricultural expansion has often come at the expense of natural landscapes such as forests. Given the growing body of research which shows the importance of forests for nutrition in many low- and middle- income countries, careful consideration must be given to the types of food production systems we adopt in the future. Forest conservation and restoration is likely to not only be critical for ensuring nutrition security for some of the world’s poorest people, but also for tackling climate change and biodiversity loss, which are all key outcomes of the global Sustainable Development Goals.

Figure 1. Micronutrient supply in all future scenarios was inadequate to meet population-level requirements, except for zinc in a “best-case” scenario (SSP1/RCP 4.5).