Food security occurs when all members of a household have reliable access to food in sufficient quantity and quality to maintain an active and healthy lifestyle. Given the important biological and social value of food for humans, food and food sufficiency have been traditional topics of study among biological anthropologists. The focus on food insecurity, however, has emerged within the past two decades and recent global events, including the food crisis of 2007/2008, have led to renewed interests in the topic of food insecurity and wellbeing. Here, we review current and novel threats to food security, current thinking on measurement and definitions, and then outline a model that links food insecurity to coping strategies and then to health outcomes. We suggest that coping strategies are typically context-specific and can be food and nonfood based. We further suggest that coping strategies may impact health quite broadly, not just through nutritional pathways. We then review available data on the relationship between food insecurity and nutritional status, chronic diseases, infectious diseases, and mental health. Our review highlights the far reaching consequences of food insecurity for human wellbeing but also the considerable variability in its effect and our limited empirical knowledge of the pathways through which food insecurity impacts health. We conclude by offering thoughts on how biological anthropologists might contribute to growing our understanding of food insecurity and human health and wellbeing. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.