Implementation of menu labelling interventions in the out-of-home food environment

Background: Prevention of obesity is a public health priority both globally and in Ireland. While the causes of obesity are complex and multifaceted, poor diet is a leading risk factor. Labelling menus with nutrition information has gathered growing public and legislative support in response to the increased consumption of foods prepared outside the home and the associated risks of poor dietary quality and increased body weight. Evidence shows that menu labelling has positive effects on consumer food choices and industry/catering practices; however, challenges to implementation have arisen. To date, no previous review has synthesised the evidence on the determinants of menu labelling implementation. Moreover, few studies report the extent to which menu labelling is implemented as designed. Aims: The overall aim of this thesis is to contribute to the evidence base on implementation of menu labelling interventions in the out-of-home food environment, with the goal of shaping policy to reduce overweight and obesity. In line with this aim, the research sought to (i) synthesise the evidence on the barriers and facilitators to implementing menu labelling interventions from a food service industry perspective, and (ii) assess the levels of implementation fidelity to a calorie posting policy in Irish public hospitals; and to identify the perceived factors influencing implementation, and in particular, factors specific to fidelity. Methods: The systematic review of peer-reviewed and grey literature followed the steps of the ‘best fit’ framework synthesis approach and incorporated a combination of deductive and inductive analysis techniques. There were no restrictions on menu labelling scheme or format, study methods, publication year or language. The mixed methods study used a sequential design (quant → QUAL), with a nested case study consisting of four acute public hospitals for the qualitative component. A triangulation protocol was used to integrate fidelity findings from multiple sources. Data on influencing factors and fidelity were then combined using joint displays for within and cross-case analysis. To help systematically evaluate the determinants of implementation, both studies were guided by the Consolidated Framework for Implementation Research. Results: The review, which found 17 eligible studies, identified multiple interdependent factors influencing implementation of menu labelling interventions, many of which acted simultaneously as barriers and facilitators. Factors influencing implementation were predominantly related to key characteristics of the menu labelling intervention as well as factors operating within the internal setting of food businesses and external context of food businesses. Based on the review findings, an adapted CFIR framework consisting of a priori and new constructs was constructed to illustrate how factors interact to influence implementation effectiveness of menu labelling interventions from a food service industry perspective. Findings from the quantitative phase of the mixed methods study revealed seven hospitals were categorised as low implementers and 28 hospitals were high implementers of the calorie posting policy. Across the four hospitals selected as cases for the qualitative phase, integrated analysis of fidelity from both phases indicated a pattern of partial adherence to the calorie posting policy. Across the four hospitals, factors influencing implementation and fidelity were multiple, and operated independently and in combination. Factors were related to the internal hospital environment, external hospital environment, features of the calorie posting policy, and the implementation process. Conclusion: This research includes the first systematic review to focus on the determinants of menu labelling implementation. The mixed method study is also one of few studies, with none in the healthcare setting, to examine fidelity to a calorie menu labelling policy. The overall research findings point to the need for menu labelling legislation with adequate monitoring and enforcement as well as increased consumer demand. Future research should assess other dimensions of fidelity, document and track adaptations to menu labelling interventions, and develop and test implementation strategies to address the determinants identified in the current research