This paper deals with the study of functional foods and its importance in health, with the development of resistant cassava starch (ARM) performed on two levels: the theoretical or conceptual and experimental. The methodology involved the steps for the production of ARM, taking the cassava starch (sweet cassava) treated with food grade chemicals and evaluated experimentally "in vitro" and "in vivo". Allied to this step we constitute a study of functional foods in order to establish a theoretical framework for conceptualizing the development this type of food. In the case of modified cassava starch to take resistant starch, the results indicate an opening for further research in the field of functional foods.