Germinated brown rice (GBR) is a functional food, whose benefits for chronic diseases have been demonstrated by scientific research on a single constituent of GBR, gamma aminobutyric acid. This article examines the processes through which the emphasis on biomedical rationality made during the production and consumption of functional foods is embedded in the complicated social contexts of the post-1990s. In the case of GBR, the Korean government, food scientists, mass media and consumers have added cultural accounts to the biomedical understanding of foods. In particular, consumers have transformed their households and online communities into a place for surveillance medicine. Functional foods are embedded in multiple actors’ perspectives on what healthy foods mean and how and where the risks of chronic diseases should be managed.