Food and beverage product reformulation is a public health nutrition policy of recent prominence; it is a so-called 'win-win' policy, as unlike other nutrition policies it has the potential to also benefit the food and beverage industry. However, reformulation has also been criticized as being driven by industry interests. In order to inform future policy debates about reformulation, we sought to investigate how and why reformulation became a public health initiative by conducting a framing analysis on 278 U.S. newspaper articles from 1980 to 2015. Frames are aspects of text which emphasize a particular definition of a problem or solution, and were chosen as the focus of this research as they help shape policy discourses and guide which policies come onto the public policy agenda. Three primary frames of reformulation were identified: business, health and political. Having multiple frames instills reformulation with the ability to assume different meanings in different contexts, which helps to explain how it has garnered broad support from multiple sectors. The political frame of reformulation, however, only grew in importance after 2001, to describe reformulations occurring in response to public health policy initiatives aimed at obesity and noncommunicable diseases. The increasing use of a political frame, and the events described in the articles, suggest that voluntary reformulation followed a growing threat of policy change and litigation facing the industry, a finding that provides important context to debates about voluntary reformulation initiatives. Future reformulation initiatives will need to reconcile and negotiate the varying frames and aims of reformulation in order to ensure they are a success from the public health perspective.