Human biology and notions of health and wellbeing are deeply social and historical phenomena, and political and socio-economic processes that cross spatial and temporal scales contribute to observable variation in human welfare. This dissertation examines the production of human health and wellbeing among Mikea people living in southwestern Madagascar as broad social changes, including new forms of regional environmental governance and the gradual establishment of a new protected area influence changing relationships among subsistence producers, the state and national society, and the biophysical environment. Primary research participants live in three villages in the northern and central Mikea Forest region and share a degree of common history and kinship. At the same time, the geographic distribution of field sites reflects regional variation in local ecology, subsistence and lifestyle, exposure to environmental policies, and access to infrastructure. In order to understand associations between changing access to social, political, and environmental resources and relative wellbeing among Mikea, this dissertation examines the production of regional environmental discourses and environmental policies that restrict livelihoods and induce resource scarcity, variation in nutritional status, perceived health and morbidity, and patterns of healthcare decision-making. I find that environmental discourses, including the discourse of Mikea indigeneity, that figure prominently in regional environmental policies exacerbate regional inequalities and have entrenched institutional biases against subsistence producers in general and against Mikea people in particular. Mikea act to manage risk and cope with insecurities related to subsistence and long-standing social and economic inequalities, but exposure to social shocks and environmental policies that restrict or criminalize subsistence activities and can overburden coping abilities, creating vulnerabilities. Vulnerabilities manifest as significant site-wise and gendered disparities in the nutritional status of adults and children, in perceived health and morbidity, and in access to healthcare resources in the Mikea Forest region. By inducing resource scarcity, new forms of environmental governance alter access to resources that sustain livelihoods and traditional modes of medical practice among Mikea, while opportunities to access markets, technology, medicine, and public health resources is not increasing to satisfy emergent social and material needs.