Regulatory measures are among the strategies for the promotion of adequate and healthy diet recommended by the Brazilian National Food and Nutrition Policy (PNAN). Although other actions in the promotion of adequate and healthy diet have made strides in Brazil, regulatory measures have made slow progress. The study aimed to identify and describe factors related to the development and implementation of the principal regulatory measures for the protection of adequate and healthy diet in Brazil in the last 20 years. This qualitative document study assessed a series of federal regulatory measures for the protection of adequate and healthy diet proposed or in discussion from 1999 to 2020. They include the regulation of food advertising, regulation of food product marketing in schools, implementation of mandatory front-of-package labeling on foods, and taxation of sugary drinks. Most of the barriers identified were strategies in corporate political activity led by the private sector, especially by the food industry. The Corporate political activity practices used in the various stages of policy processes include legal actions against the State, substitution of policies (suggesting voluntary or ineffective alternatives), opposition, fragmentation, and destabilization with attempts at support from the community. During the study period, none of the measures was approved. Given this scenario, barriers to the approval of regulatory measures for the protection of adequate and healthy diet need to be overcome in Brazil.