In the last few years, Mexico adopted public health policies to tackle non-communicable diseases (NCDs), such as front of package nutrition labelling, food marketing restrictions to children, and a soda tax. In parallel, transnational food and beverage industries (F&BIs), their allies, and the government have agreed on public-private partnerships (PPPs) to implement policies or deliver programs. However, research has questioned the benefits of PPPs and exposed its limitations as a suitable mechanism to improve public health. This study analyses how four PPPs between the Mexican government, the F&BI, and allies are working to achieve their goals. We critically assessed the objectives, scope, reported impacts, governance principles and perceived risks and benefits for the public health agenda of these PPPs. This qualitative study is based on 26 interviews with key actors, and 170 publicly available documents, including 22 obtained through freedom of information (FOI) requests related to four purposively selected PPPs aiming to improve health. We found that the four PPPs studied had minimal public information available on their implementation and impact. The private partners tend to dictate the design, information management, and implementation of the programs, while promoting their brands. Few independent evaluations of the PPPs exist, and none reported on their effectiveness or public health benefits. Good governance principles, such as accountability, transparency, fairness, participation, integrity, and credibility, were barely followed in each of the cases studied. Public officials did not automatically question the conflict of interest (CoI) of such arrangements. When there were COI, the potential risks these posed did not always outweigh the financial benefits of working with the F&BI and its allies. The four PPPs studied produced minimal gains for public health while boosting credibility for the participating transnational F&BIs. It shows the lack of awareness of how these PPPs might be hindering public health gains.