Abstract
<title>Abstract</title> <p>Background Previous research has revealed incomplete implementation of the national school food standards (SFS) in secondary schools in England. Normalization Process Theory (NPT) offers a framework for assessing the implementation and embedding of new interventions. We aimed to use NPT to understand school staff perspectives on SFS implementation in secondary schools. Methods A mixed methods study comprising a cross-sectional survey and qualitative interviews with staff in secondary schools in England. We used NPT to frame survey questions and interview topic guides. Interview transcripts were thematically analysed. Descriptive survey results and qualitative themes were integrated and mapped onto NPT constructs using a joint display. Results Staff from 32 schools completed the survey (n = 181, 52% response) and 21 participants from four schools completed interviews. Qualitative analysis resulted in 10 sub-themes within four over-arching NPT constructs. Coherence (construct 1): SFS supported menu planning, however, there was dissonance between SFS requirements and the contextual factors influencing school food provision. Half of survey respondents reported understanding what is required of them in relation to SFS implementation. Cognitive participation (construct 2): was generally low, especially in senior leadership and governors. Collective action (construct 3): survey data suggested that school teams did not work well together to implement the SFS, however qualitative data indicated some potentially supportive actions e.g. external support, resource allocation, shared motivations and open communication. Reflexive monitoring (construct 4): SFS were considered worthwhile, but there was an absence of monitoring. Conclusions Use of mixed methods integration within a NPT framework identified factors that support or restrict implementation of the SFS in secondary schools. Challenges include the influence of competing decision drivers and low staff legitimation, whilst supportive actions include linking school food to salient issues for schools, assignment of responsibility and resources, providing training and support, and systematic monitoring. Trial registration: ISRCTN 68757496 (registered 17 October 2019).</p>