This study examines gender differences in household food security in East Africa and implications for climate change adaptation. The study uses survey data from 600 households in 68 villages across three sites in Uganda, Kenya and Tanzania. Logistic regression analysis found that crop diversification, higher productivity (crop yields), and incomes are positively correlated with increased food security, while female-headed households are less food secure than male-headed households. The study concludes that actions to address inequalities in governance systems and institutions supporting food systems, as well as social norms, could significantly improve household food security, especially for female-headed households through increased access to productive assets, extension services, and practices that encourage diversification and productivity.