Dimensionality and psychometric properties of an Italian translation of the Intuitive Eating Scale-2 (IES-2): An assessment using a bifactor exploratory structural equation modelling framework

Abstract

The construct of intuitive eating is most often measured using the 23-item Intuitive Eating Scale-2 (IES-2), but previous studies have typically relied solely on confirmatory factor analysis (CFA) to understand IES-2 dimensionality. In contrast, a bifactor exploratory structural equation modelling (B-ESEM) framework offers a more realistic account of IES-2 multidimensionality. Here, we assessed the psychometric properties of a novel Italian translation using a combination of exploratory factor analysis and B-ESEM. A total of 950 adults completed the IES-2 alongside measures of positive body image, disordered eating, and psychological well-being. Results indicated that a 4-factor B-ESEM model had adequate fit to the data and that fit was improved when the correlated uniqueness of seven negatively worded IES-2 items was accounted for. This model of IES-2 scores showed adequate internal consistency and good test-retest reliability up to three weeks. Evidence of construct validity was good in terms of a global IES-2 factor, and broadly supported in terms of its specific-factors. These results highlight the utility of a B-ESEM framework for understanding the dimensionality of IES-2 scores and may help scholars better understand the extent to which the IES-2 adequately operationalises the construct of intuitive eating.

Keywords: Bifactor analysis; Eating styles; Exploratory structural equation modelling; Intuitive eating; Italy; Test adaptation.