Jessica Evelyn Raneri

Ecological diversity indices such as Hill numbers have been developed to estimate effective species numbers, yet the ability of Hill numbers to compare food biodiversity across contexts is unclear. Here we computed the between- and within-country variability of similarity-insensitive Hill numbers using dietary intake collected from prospective cohorts in nine European countries and cross-sectional studies in five low- and middle-income countries. We also assessed the relationships between more biodiverse diets, mortality rates and micronutrient adequacy. Only Hill₀, better known as dietary species richness (DSR), showed strong heterogeneity between countries and individuals within countries. Higher DSR was most strongly associated with lower mortality rates in Europe as compared to Hill₁, Hill₂ and Hill_∞, whereas relationships with micronutrient adequacy were comparable across Hill numbers in the global south. DSR can be used to assess progress towards more biodiverse diets, while also serving as a marker for the deleterious nutrition and health impacts associated with non-diverse diets.

Indigenous food systems of Pacific Small Island Developing Countries contain vast biological and cultural diversity. However, a nutrition transition is underway, characterized by shifts away from traditional diets in favour of imported and modern foods, contributing to some of the highest rates of obesity and Diabetes Type 2 Mellitus in the world. Using a mixed method approach, this study aimed to assess dietary agrobiodiversity’s relationship with nutrition indicators related to diet quality and anthropometrics within the context of the rural and Indigenous food system of Baniata village, located in the Western Province of Solomon Islands (Melanesia). A secondary aim was to evaluate the contribution of agrobiodiversity from the local food system to diet quality. A comprehensive nutrition survey was administered to the women primarily responsible for cooking of randomly selected households (n = 30). Additionally, 14 participatory focus group discussions captured the historical narrative of food system transitions, were hosted over a period of seven days, and included men, women and youth. Dietary intakes of the participants were reported below the estimated average requirement (EAR) for several essential nutrients, including protein (53%), calcium (96.6%), vitamin B1 (86.6%), vitamin B2 (80%), vitamin A (80%), zinc (40%) and fibre (77%). Focus group participants built a timeline of key historical and climatic transitions perceived to be drivers of dietary shifts away from traditional foods and towards imported and processed foods. Participants identified 221 species and varieties of agrobiodiverse foods available for cultivation or wild collection. Based on 24 h diet recalls, 87 were found to be utilised. Participants who consumed foods of a wider diversity of species richness had a higher probability of achieving recommended nutrition intakes and a lower body fat percentage (r² = 0.205; p = 0.012). Our results suggest a nutrition transition is underway, and strategies harnessing traditional knowledge of nutrient-dense, agrobiodiverse foods can help improve food and nutrition security.

Indigenous Solomon Islanders, like many living in Pacific Small Island Developing States (PSIDS), are currently experiencing the global syndemic—the combined threat of obesity, undernutrition, and climate change. This mixed-method study aimed to assess nutrition transitions and diet quality by comparing three geographically unique rural and urban indigenous Solomon Islands populations. Participants in rural areas sourced more energy from wild and cultivated foods; consumed a wider diversity of foods; were more likely to meet WHO recommendations of >400 g of non-starchy fruits and vegetables daily; were more physically active; and had significantly lower body fat, waist circumference, and body mass index (BMI) when compared to urban populations. Urban populations were found to have a reduced ability to self-cultivate agri-food products or collect wild foods, and therefore consumed more ultra-processed foods (classified as NOVA 4) and takeout foods, and overall had less diverse diets compared to rural populations. Clear opportunities to leverage traditional knowledge and improve the cultivation and consumption of underutilized species can assist in building more sustainable and resilient food systems while ensuring that indigenous knowledge and cultural preferences are respected.

The global food system is causing large‐scale environmental degradation and is a major contributor to climate change. Its low diversity and failure to produce enough fruits and vegetables is contributing to a global health crisis. The extraordinary diversity of tropical tree species is increasingly recognized to be vital to planetary health and especially important for supporting climate change mitigation. However, they are poorly integrated into food systems. Tropical tree diversity offers the potential for sustainable production of many foods, providing livelihood benefits and multiple ecosystem services including improved human nutrition. First, we present an overview of these environmental, nutritional and livelihood benefits and show that tree‐sourced foods provide important contributions to critical fruit and micronutrient (vitamin A and C) intake in rural populations based on data from sites in seven countries. Then, we discuss several risks and limitations that must be taken into account when scaling‐up tropical tree‐based food production, including the importance of production system diversity and risks associated with supply to the global markets. We conclude by discussing several interventions addressing technical, financial, political and consumer behaviour barriers, with potential to increase the consumption and production of tropical tree‐sourced foods, to catalyse a transition towards more sustainable global food systems. A free Plain Language Summary can be found within the Supporting Information of this article.

Malnutrition linked to poor quality diets affects at least 2 billion people. Forests, as well as agricultural systems linked to trees, are key sources of dietary diversity in rural settings. In the present article, we develop conceptual links between diet diversity and forested landscape mosaics within the rural tropics. First, we summarize the state of knowledge regarding diets obtained from forests, trees, and agroforests. We then hypothesize how disturbed secondary forests, edge habitats, forest access, and landscape diversity can function in bolstering dietary diversity. Taken together, these ideas help us build a framework illuminating four pathways (direct, agroecological, energy, and market pathways) connecting forested landscapes to diet diversity. Finally, we offer recommendations to fill remaining knowledge gaps related to diet and forest cover monitoring. We argue that better evaluation of the role of land cover complexity will help avoid overly simplistic views of food security and, instead, uncover nutritional synergies with forest conservation and restoration.

Assessing progress towards healthier people, farms and landscapes through nutrition-sensitive agriculture (NSA) requires transdisciplinary methods with robust models and metrics. Farm-household models could facilitate disentangling the complex agriculture-nutrition nexus, by jointly assessing performance indicators on different farm system components such as farm productivity, farm environmental performance, household nutrition, and livelihoods. We, therefore, applied a farm-household model, FarmDESIGN, expanded to more comprehensively capture household nutrition and production diversity, diet diversity, and nutrient adequacy metrics. We estimated the potential contribution of an NSA intervention targeting the diversification of home gardens, aimed at reducing nutritional gaps and improving livelihoods in rural Vietnam. We addressed three central questions: (1) Do ‘Selected Crops’ (i.e. crops identified in a participatory process) in the intervention contribute to satisfying household dietary requirements?; (2) Does the adoption of Selected Crops contribute to improving household livelihoods (i.e. does it increase leisure time for non-earning activities as well as the dispensable budget)?; and (3) Do the proposed nutrition-related metrics estimate the contribution of home-garden diversification towards satisfying household dietary requirements? Results indicate trade-offs between nutrition and dispensable budget, with limited farm-household configurations leading to jointly improved nutrition and livelihoods. FarmDESIGN facilitated testing the robustness and limitations of commonly used metrics to monitor progress towards NSA. Results indicate that most of the production diversity metrics performed poorly at predicting desirable nutritional outcomes in this modelling study. This study demonstrates that farm-household models can facilitate anticipating the effect (positive or negative) of agricultural interventions on nutrition and the environment, identifying complementary interventions for significant and positive results and helping to foresee the trade-offs that farm-households could face. Furthermore, FarmDESIGN could contribute to identifying agreed-upon and robust metrics for measuring nutritional outcomes at the farm-household level, to allow comparability between contexts and NSA interventions.