Intra- and Interpersonal Dimensions of Orthorexia: Preliminary Development and Validation of an Intra- and Interpersonal Effects Scale for Orthorexia.

Orthorexia nervosa (ON) is a disorder characterized by dietary restrictions and an obsessive focus on "healthy" eating. The present study analyzes two aspects of ON. One related to the inner experiences of the individual (intrapersonal). The other concerns the impact of ON on interpersonal relationships (interpersonal). The developed scale was named the Intra- and Interpersonal Effects Scale of Orthorexia (IIESO). The analysis showed an average correlation between the INTER and INTRA factors (r = 0.46). Both the INTER and INTRA scales correlated strongly with both subscales of the TOS but weakly with the ORTO-R score. Females obtained higher scores on the INTER scale ( p < 0.01), while no differences were shown for the INTRA subscale or the overall scale score ( p < 0.01). Subjects using supplements had higher mean scores on the INTER and INTRA subscales and for the total score. Among the analyzed results, the greatest strength effect was shown for the total score on the IIESO scale (INTER+INTRA) and the TOS scale. The questionnaires used to date have not distinguished between behaviors from interpersonal and intrapersonal perspectives. Research on these dimensions could expand our knowledge of the disorder and refine diagnostic criteria.