Abstract What influences government policymaking? The case of childhood obesity in England | Dolly Rose Zarina Theis In England today, four out of the top five risk factors of healthy life years lost to death, disability and disease are related to diet and physical activity. The government has proposed hundreds of policies since the early 1990s related to these behaviours. Such policy has largely been presented as ‘obesity policy’, or at least presented as solutions to tackle increased obesity prevalence and related inequalities. In 1993, 58% of men, 49% of women and 25% of children aged 2 to 15 in England were living with obesity or excess weight, which increased to 68%, 60% and 30% respectively by 2019. The aim of this thesis was to investigate why, after 30 years of government obesity policy, has obesity prevalence and related inequalities not been successfully reduced, and in particular to understand how and why government obesity policy comes about. Study 1 was a mixed-methods analysis of all government obesity strategies and policies in England published between 1992 and 2020 using a theory-based analytical framework, content analysis and applied thematic analysis. The interpretation drew on both thematic analysis and quantitative findings. I found that the government has published 14 strategies either wholly or partially dedicated to tackling obesity in England in the last 30 years and that these have contained 689 individual policies. Policies have largely been proposed in a way that does not readily lead to implementation; the majority rely on individuals to change their own behaviour rather than making that easier by shaping external influences; and the government has relied more on voluntary rather than regulatory measures. The findings indicate that the government’s failure to tackle obesity so far may not only be due to the nature and types of policies proposed, but also the way government has proposed them. Drawing on Study 1, I adopted a pragmatic approach to conduct an in-depth case study to understand how one of the 14 obesity strategies – Childhood Obesity: A plan for action (2016) (COP) – came about. Study 2 applied theory-testing process-tracing to examine how COP came about, including what (e.g., evidence and events) and who was most influential, and study 3 also applied theory-testing process- tracing to examine the particular role of policy entrepreneurs by analysing the influence of celebrity chef and campaigner Jamie Oliver. I developed a novel theoretical conceptual framework combining the core concepts from three policy process theories – Multiple Streams Framework, Advocacy Coalition Framework and Punctuated Equilibrium Theory - to test in Study 2, and for Study 3, I tested Aviram et al.’s (2020) policy entrepreneur framework. 2 I found that policy process and policy entrepreneur theory helped to explain the key influences in the policy process, but not necessarily the causal order or relative importance at particular times. In Study 2, I found that the government policy process leading up to COP published in 2016 involved all key conditions for policy change, as identified in previous studies, but it was the substantial expert-seeking activities, political will-building between key political actors, actions of policy entrepreneurs, key institutional factors (political cycles and changes in government), and policy windows that enabled it to result in policy change. Many of these influences were more influential after the government’s decision agenda had been set and policy formation had begun. The case showed how much of the most important policy processes were largely hidden from public view and even from members of government. For example, the Soft Drinks Industry Levy (SDIL) was almost an entirely hidden policy process until it was announced in the March 2016 Budget and demonstrated the potential effectiveness of political considerations in increasing policy experimentation and innovation, as it led to the tailored sugar tax design. The case also demonstrated how exogenous events can obstruct policy and political continuity. In Study 3, I found that the most influential strategies involved a combination at first to build momentum around a particular policy problem and solution, followed by gaining access to decision- makers and strategically using symbols and storytelling to frame issues and solutions persuasively. He demonstrated how effective being “relentless but practical” can be, i.e., not relenting in efforts to achieve policy change, but recognising that political decision-making is difficult, so welcoming even imperfect policy change or progress. The findings in this thesis shed novel light on government obesity policy and the related policy process in England, emphasising that process is just as important as the policy ideas themselves. The substantial scale and scope and methodological nature of the research conducted in this thesis provides a broad and deep understanding of government obesity policymaking in England, with several key implications for policy, practice and research. The thesis sheds light on the substantial gap in empirical research that uses and applies theory on the government obesity policy process, particularly in the context of England. The studies help fill that gap whilst offering guidance on possible future research, including critically assessing the quality of the most influential evidence used in the policy process or comparative research that analyses the government obesity policy process under different governments or between different countries. The thesis also provides useful learnings for policy and practice, including how to propose policies in a way that more readily leads to implementation, how to create conditions that increase the chance of policy change, and what strategies and traits to use to influence the policy process more effectively.