Understanding the Pathways From Agricultural Biodiversity to Dietary Diversity and Nutritional Outcomes in Smallholder Farming Communities in Middle Belt Nigeria

Agricultural biodiversity, encompassing the variety of crops, livestock, and wild foods maintained within farming systems, is theoretically linked to household dietary diversity and nutritional outcomes, but the mechanisms and pathways through which this relationship operates remain contested and context-specific. This study investigated pathways from agricultural biodiversity to dietary diversity and nutritional outcomes in smallholder farming communities in the Middle Belt zone of Nigeria, specifically in Benue, Plateau, and Nasarawa States. A theory of change framework was developed and tested using a two-round panel survey of 420 farming households, complemented by a biodiversity assessment of farm plots and participatory dietary recall. Farm-level species richness was measured using standardised biodiversity indices for crop, tree, and livestock components. Household dietary diversity was assessed using the Food Consumption Score and Women's Dietary Diversity Score. Child and maternal nutritional outcomes were evaluated through anthropometry and haemoglobin measurement. Pathway analysis was conducted using structural equation modelling. Results showed that farm species richness had a significant indirect effect on dietary diversity, mediated by market access, own consumption decisions, and women's land control. Direct pathways from biodiversity to consumption were significant only in households with limited market integration. Maternal education and season moderated pathway effects. The study advances the theoretical and empirical understanding of agriculture-nutrition linkages in Middle Belt Nigeria and informs biodiversity-sensitive nutrition programming. Keywords: agricultural biodiversity, dietary diversity, nutritional outcomes, Middle Belt Nigeria, smallholder farming