A systematic review of barriers to adopting a plant-based diet (PBD) in high-income countries (HICs) identified 40 barriers grouped into 11 themes: financial, lack of knowledge, emotional, health, convenience, social, enjoyment of meat, environmental, accessibility, personal ability, and media. The most supported barriers were nutritional intake/requirements (health theme) and habits (personal ability theme). Nutritional concerns included fears of not meeting dietary needs on a PBD, while habits involved established eating patterns and reliance on animal-source foods. Education interventions and communication/marketing policies were identified as key strategies to address these barriers. The review included 10 studies with 1740 participants, five qualitative, four cross-sectional, and one pre- and post-intervention study. The COM-B model was used to categorize barriers into capability, opportunity, and motivation. The review found that nutritional intake/requirements had the most evidence, followed by lack of knowledge. Other barriers included financial constraints, social pressures, and the enjoyment of meat. The study also highlighted the importance of addressing these barriers through targeted interventions and policies to promote PBD adoption. The findings suggest that education, awareness, and support networks are crucial for overcoming the challenges associated with adopting a PBD. The review emphasizes the need for further research and tailored strategies to address the specific barriers faced by individuals in HICs.A systematic review of barriers to adopting a plant-based diet (PBD) in high-income countries (HICs) identified 40 barriers grouped into 11 themes: financial, lack of knowledge, emotional, health, convenience, social, enjoyment of meat, environmental, accessibility, personal ability, and media. The most supported barriers were nutritional intake/requirements (health theme) and habits (personal ability theme). Nutritional concerns included fears of not meeting dietary needs on a PBD, while habits involved established eating patterns and reliance on animal-source foods. Education interventions and communication/marketing policies were identified as key strategies to address these barriers. The review included 10 studies with 1740 participants, five qualitative, four cross-sectional, and one pre- and post-intervention study. The COM-B model was used to categorize barriers into capability, opportunity, and motivation. The review found that nutritional intake/requirements had the most evidence, followed by lack of knowledge. Other barriers included financial constraints, social pressures, and the enjoyment of meat. The study also highlighted the importance of addressing these barriers through targeted interventions and policies to promote PBD adoption. The findings suggest that education, awareness, and support networks are crucial for overcoming the challenges associated with adopting a PBD. The review emphasizes the need for further research and tailored strategies to address the specific barriers faced by individuals in HICs.