Barriers and facilitators to the implementation of nutrition standards for school food: a mixed-methods systematic review protocol.

The importance of nutrition during childhood and the high prevalence of child and adolescent obesity has resulted in several countries implementing nutritional standards for school food as a way of providing healthy school food environments. Yet, there has been less focus on the barriers and facilitators influencing the process of implementing school food standards. This mixed-methods systematic review aims to address this evidence gap by synthesising the empirical evidence on the factors that may influence the implementation of school food standards. This mixed-methods systematic review will use qualitative, quantitative and mixed-methods evidence from peer-reviewed publications retrieved from the following databases; PubMed, CINAHL, Scopus, EMBASE, Medline, PsycINFO and Web of Science. Grey literature will be accessed through Google Scholar, Open Access Theses and Dissertations, OpenGrey, RIAN, EThOS, ProQuest, WorldCat, Networked Digital Library of Theses and Dissertations, and public health organisation websites will also be accessed. Screening reference lists and citation chaining of all included studies will also be undertaken. No restrictions on publication date or language will be applied, however, only primary research studies relevant to supply-side stakeholders will be eligible for inclusion. Study quality will be assessed using the Mixed Methods Appraisal Tool. Study titles and abstracts will be screened to decide whether the full-text manuscript should be retrieved. For screening reliability, a second review author will assess a random sample of 20%. Kappa statistics will be used to assess inter-rater reliability, with values of 0.75 and higher representing high agreement. Two authors will independently extract data and factors reported to influence implementation. This will be synthesized using the Theoretical Domains Framework. A comprehensive understanding of these factors can provide guidance to relevant stakeholders to enhance the adoption, implementation and sustainability of nutrition standards for school meals. : PROSPERO CRD42019117904.