Manuscript - Protocol paper

The design and methodological framework of the study were described in a protocol paper outlining the aims, design, and planned multimodal assessments of the Comprehensive Risk Evaluation for Anorexia Nervosa in Twins (CREAT) study. This paper details the co-twin control design involving monozygotic twins discordant for anorexia nervosa and concordant control twin pairs, and describes the broad range of phenotypic and biological assessments included in the study, spanning endocrinology, neurocognition, neuroimaging, genomics, and multi-omic approaches. The protocol also outlines the experimental component examining responses to an overnight fast. By documenting the study design and analytic framework, the protocol provides a transparent foundation for the program of work arising from CREAT and supports interpretation of the subsequent empirical findings generated through the project.