Clinical staging models in psychiatry assert that there are earlier, less severe or more malleable forms of illness that are distinguishable from later, more chronic forms of illness, and that these stages may have different prognostic and treatment implications. Previous reviews on clinical staging in eating disorders (EDs) suggest a staging heuristic could be useful for anorexia nervosa, but less research is available on how this applies to other EDs. An up-to-date review is required to synthesise new and heterogenous avenues of research. This scoping review aims to explore the extent and types of evidence in relation to illness staging for EDs and how these concepts are associated with treatment response and outcomes.

This protocol was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol extension for Scoping Reviews checklist and the Joanna Briggs Institute Reviewer’s Manual. We will consider any documents providing evidence for clinical staging such as those which describe full or partial staging models, for all EDs, across various domains of assessment and functioning. Participants will include clinical or non-clinical population samples with full-syndrome EDs or disordered eating behaviour. PubMed, PsycINFO, MEDLINE and Web of Science databases will be systematically searched for relevant literature. Two authors will export documents and screen titles, abstracts and full texts. Data will be extracted into a charting form drafted by the authors. A narrative summary of the documents will be conducted in line with the study aims. Finally, clinical and research recommendations will be outlined.

Ethical approval will not be required to synthesise published and unpublished literature. The study will be published in a peer-reviewed journal and shared at conferences, via social media, and in other communications.