Forests have, historically, had a very important role in food security in upland areas of South and Southeast Asia – both as sources of wild food and as sites for grazing, planting food trees and bushes, and various types of shifting agriculture. However, since at least the early 20th century, agricultural development and forest management have been treated as discrete policy areas, with separate institutions. Here we show how natural resource management policies and institutions influence livelihoods and food security for communities in upland areas of Thailand, Vietnam and Nepal.