title: Out-of-home influences on eating behaviour and health
Creators: name: Finlay, Amy
Publisher: name: University of Liverpool Repository
Year: 2024

description: The food environment is likely a key contributor to population-level obesity, and the increased rates of obesity in more socioeconomically disadvantaged groups. There are a number of features of the food environment that encourage unhealthy behaviours, and often undermine individual attempts to improve health. Key aspects of this ‘obesogenic’ environment include food marketing and the increased availability of food prepared outside of the home (OOH). Preventative public health policies are recognised as a means to lessen the harms of the food environment. However, to inform such policies, research should determine the extent that different aspects of the environment negatively influence behaviour and health, and the potential of policies to reduce this influence. The overarching aim of this thesis is to consider OOH food environment influences on obesity and potential policies to reduce their negative influence on consumer behaviour. 
Chapters 2 and 3 aimed to quantify outdoor food marketing exposure, power and impact. Chapter 2 demonstrated that the majority of foods promoted in outdoor settings are unhealthy. Individuals from ethnic minority groups are more exposed to food marketing in outdoor settings compared to white populations, however findings on differential exposure by socioeconomic position (SEP) were mixed. This review also identified that what was considered ‘outdoor food marketing’ was rarely defined, and when definitions were used, they were inconsistent across studies. There was also inconsistent use of methods to measure outdoor food marketing. Chapter 3 found that many food advertisements were present on bus shelters in a deprived area of the UK (49% of all bus shelter ads). Of these food advertisements, 35% would not be permitted to be advertised on television to children in the UK as they were deemed ‘less healthy’ by the UK Nutrient Profiling Model. Across chapters 2 and 3, there was evidence that powerful creative strategies such as food images and competitions were frequently used in outdoor food marketing. Chapter 4 is a World Health Organisation protocol informed by the current research into outdoor food marketing, including the work in chapters 2 and 3. It is hoped that use of this protocol will aid the consistency of research into outdoor food marketing, facilitating the conduct of monitoring research and allowing for greater clarification of the exposure, power and impact of this marketing due to improved comparability between studies and over time. 
Chapter 5 aimed to assess associations between food marketing exposure and household nutrient purchases. The study in chapter 5 demonstrated that traditional food advertising (e.g. broadcast, print) was associated with greater purchasing of energy and some dietary nutrients (carbohydrate, protein, sugar). Category-specific associations were also observed between advertising of sugar-sweetened beverages and purchase of sugary beverages, although similar associations were not found for advertising of sugary cereals and sweet snacks. There was limited evidence of relationships between advertising exposure and diet outcomes across functional, recreational, digital, and transport marketing mediums.
The overarching aim of chapters 6 and 7 was to test intervention approaches to reduce energy intake from food prepared OOH. The study in chapter 6 found that calorie labelling of food and drink items on a virtual delivery app was associated with a reduction in calories ordered overall, and from two of three measured outlets. A proportional pricing intervention in this study (where the change in price was proportional to the change in portion size), resulted in participants choosing significantly fewer larger portion sizes. Additionally, in proportional pricing conditions participants had a significantly reduced likelihood of selecting a larger size from one of the three measured outlets. Finally, the two experiments in chapter 7 examined meal size and energy intake in response to foods at lower (&lt;1.5kcal/g), medium (1.7-2.0kcal/g) and higher (≥3.0kcal/g) levels of energy density (ED). Results demonstrated that foods higher in ED, which is frequent for foods prepared OOH, were associated with significantly greater energy intake, supporting the proposition that policies to promote reductions to food product ED would be predicted to decrease population level energy intake. 
Overall, this thesis supports the proposition that the food environment contributes to unhealthier diets and that intervention approaches to address the OOH food environment hold promise in improving population level diet and obesity. The findings from this thesis can be used to inform the development of public health policies and guide future research to effectively support improvements in population health.