This paper provides new empirical evidence on the nexus between farm production diversification and household diet diversity in East Africa. Starting with a conceptual framework for the pathways from agriculture to nutrition, we use data collected from a sample of ultra-poor, labor constrained families living in five rural districts of Kenya. We find production diversification to be positively and significantly associated with household diet diversification, with poultry ownership most strongly correlated. These findings suggest that supporting investments in diversified livelihood systems in general and in small livestock assets such as poultry in particular are viable intervention classes to improve household food security and nutrition for very poor, marginalized smallholders.