Forests, trees and agroforestry play a key, often undervalued, role to support food security and nutrition (FSN), in its four dimensions (availability, access, utilization and stability).• Forests, trees and agroforestry provide:(i) diverse and nutritious foods (such as nuts, oils, vegetables -leaves, flowers, roots -, fruits, bushmeat, fish, herbs, saps, mushrooms, tubers and insects), and feed for livestock;(ii) bioenergy for cooking and boiling water;(iii) income and employment (both formal and informal); and (iv) ecosystem services indispensable for agriculture and food production, now and in the future.• All these contributions need to be better considered by policies aiming at strengthening food security and nutrition, towards SDG2.• The contributions of forests and trees to FSN allow a broader and richer understanding of the notion of people's "forest dependence", with local to national and global dependences.• Maximizing the contributions of forests, trees and agroforestry to FSN requires policy coherence and integrated landscape approaches.• Agricultural policies need to better integrate the specificities of tree crops and the multiple benefits provided by the integration of trees in farming systems.