Non-communicable diseases (NCDs) such as diabetes, cancers, and cardiovascular disease, share modifiable risk factors, with overweight and obesity, physical inactivity, and poor nutrition being among the most important of these. One public health strategy that has been widely employed to address these risk factors and reduce the burden of NCDs is mass media campaigns (MMCs). These campaigns use multiple channels – including television, radio, billboards, online, and increasingly social media – to communicate messages about the promotion of health and the prevention of the disease. The aim is to reach as many people in the target population as possible, with the expectation that doing so will maximise the campaign’s impact on the population's health.
However, gaps in the scientific literature are such that knowledge about what works in NCD-related MMCs is limited. First, those campaigns that have been evaluated have consistently shown positive impacts on awareness, knowledge, and other intermediate outcomes, but it is rare for a campaign to demonstrate behaviour change. Second, the existing evidence is ageing quickly due to the rapid change in media consumption habits over the last decade, including the rapid uptake of Facebook and other social media. Finally, while there are theories, such as the Hierarchy of Effects model, that purport to explain how campaigns influence behaviour change, these have rarely been tested, meaning that their accuracy and usefulness is unknown. Collectively, these gaps make it difficult to identify effective components of MMCs, which is problematic given that governments use these types of campaigns often and that they are usually expensive to design and implement.
In this thesis, I present research that addresses these gaps. My research provides insight into the impact of MMCs on health-related outcomes and furthers our understanding of best practice in the planning, implementation, and evaluation of mass media and social media campaigns. Specifically, my research aims to identify and critique current practice within overweight and obesity prevention campaigns, identify the strengths and limitations of current practices on Facebook as a component of campaigns, and determine the impact of the recent New South Wales (NSW) Government’s Make Healthy Normal (MHN) overweight and obesity prevention campaign.
To address these aims, I conducted seven studies, using both quantitative and qualitative methods. These studies provide new and valuable insights into improving campaigns and creating engaging content on Facebook. Collectively, the findings indicate that, while campaigns can be effective in increasing knowledge about a health issue, increasing knowledge is insufficient and may not even be necessary to have a meaningful impact on health. This raises questions around the role of MMCs in responding to health issues like obesity. The research also suggests that while there is real potential to use Facebook as an effective component of campaigns, more consideration should be given to exactly what role Facebook (or other social media) should play within a broader campaign. Finally, it is important that the theories that underpin campaigns be tested and refined. Doing so will mean that effective features of communications campaigns can be identified and increase the likelihood that future campaigns will contribute to solving complex prevention problems.