Trans fatty acids (TFAs) have no known health benefits and are linked to an increased risk of noncommunicable diseases (NCDs). To eliminate TFAs from the food supply, the government of Thailand imposed a ban on partially hydrogenated oils (PHOs) in 2018. This study was aimed at analyzing the government policies and actions to eliminate TFAs in Thailand, focusing on policy content, context, process, and actors. This single-case qualitative study used a documentary review and interviews with 20 key policy actors. The data analysis was guided by thematic analysis based on the policy triangle framework. The results reveal that policy actors—government organizations, academics, civil society organizations, and the food industry—have different roles, interests, and influences with regard to eliminating TFAs in Thailand. Both formal and informal communication among policy actors aided in the policymaking process and the actions that followed. Changing perceptions of TFAs, the low intake of PHOs in Thailand, hype around trans fats, and trade dynamics shaped the government’s decision to impose the ban. As a result, the ban was selected to avoid the technical components of TFA elimination. This study suggests that eliminating TFAs in Thailand could be further enhanced by strengthening government actions in terms of enforcement and creating consumer awareness.

Ultra-processed food companies in Thailand have rapidly expanded, and they play an important role in the domestic economy and public policy. These companie