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

Validation of the Italian version of the intuitive exercise scale: a four-factor structure in the general population

PURPOSE

Intuitive exercise may foster healthier engagement in physical activity, leading to enhanced well-being and more intuitive eating habits. The Intuitive Exercise Scale (IEXS) was originally developed to assess this construct in English speakers. The IEXS is composed of four scales addressing distinct facets of intuitive exercise: emotional exercise, body trust, exercise rigidity, mindful exercise. The present study aimed to validate an Italian translation of the IEXS, exploring its factorial structure, invariance, internal consistency, and convergent validity.

METHODS

A sample of 1140 women and men (age: M = 45.25, SD = 11.64, range 22-76 years) was recruited from the Italian general population; 61.8% were physically active. Inclusion criteria were being an Italian native speaker and being at least 18 years. The sample was randomly split in two equal halves for the Exploratory Factor Analysis (n = 570; women: 50%; physically active: 61.8%) and the Confirmatory Factor Analysis (n = 570; women: 50%; physically active: 61.8%). Multi-group confirmatory factor analyses were performed to assess invariance among women and men and physically and non-physically active individuals. McDonald's omega was used to assess internal consistency. Pearson's correlations were utilized to assess convergent validity.

RESULTS

The Italian IEXS replicated a four-factor structure and showed good invariance among women and men. Invariance among physically and non-physically active individuals was only partially supported. Excellent internal consistency and adequate convergent validity were achieved.

CONCLUSIONS

The IEXS demonstrated to be a valid measure to examine intuitive exercise in the Italian population, replicating and expanding the findings of the English version. Level of evidence Level V, Cross-sectional, Psychometric study.

Measurement invariance of the Intuitive Eating Scale-2 across country, ethnicity, sex, and sexual orientation: A cross-cultural study between Brazil and the U.S

Intuitive eating is defined as being connected to internal hunger, satiety, and appetitive cues and flexibly using these cues to determine when, what, and how much to eat. The Intuitive Eating Scale-2 (IES-2) is a widely used measure of facets of intuitive eating. However, the scale has shown unstable factor structure in several validation studies and there is a lack of studies investigating the measurement invariance of the IES-2 beyond sex. We aimed to evaluate the psychometric properties of the IES-2, testing several factor structures among Brazilian and U.S. samples of men and women; to test measurement invariance across country of origin, ethnicity, sex, and sexual orientation; and to evaluate its internal consistency. Three models of the latent structure of the IES-2 were tested using confirmatory factor analyses (CFA) in a total of 1072 young adults (452 Brazilians and 620 Americans), aged 18-35 years. Results demonstrated that only a 3-factor solution with 11 items of the IES-2 showed adequate fit to the data for both countries. This model demonstrated scalar invariance across sex and sexual orientation, but only configural invariance was found across country of origin and ethnicity. Good internal consistencies were found for both the Brazilian and American samples. The present study provides support for a 3-factor solution with 11 items of the IES-2, to Brazilian and American samples. The study also offers evidence of internal consistency, and invariance between sex (i.e., male and female) and sexual orientation (i.e., heterosexual participants and sexual minority participants).

The Intuitive Eating Scale-3: Development and psychometric evaluation

Intuitive eating has been found to protect against disordered eating and preserve well-being. Yet, there are methodological (length), conceptual (inconsideration of medical, value-based, and access-related reasons for food consumption), and psychometric (item wording) concerns with its most common measure, the Intuitive Eating Scale-2 (IES-2). To address these concerns, we developed the IES-3 and investigated its psychometric properties with U.S. community adults. Across three online studies, we evaluated the IES-3's factorial validity using exploratory factor analysis (EFA; Study 1; N = 957; Mage = 36.30), as well as confirmatory factor analysis (CFA), exploratory structural equation modeling (ESEM), bifactor-CFA, and bifactor-ESEM (Study 2; N = 1152; Mage = 40.95), and cross-validated the optimal model (Study 3; N = 884; Mage = 38.54). We examined measurement invariance across samples and time, differential item functioning (age, body mass index [BMI], gender), composite reliability, and validity. Study 1 revealed a 12-item, 4-factor structure (unconditional permission to eat, eating for physical reasons, reliance on hunger and satiety cues, body-food choice congruence). In Study 2, a bifactor-ESEM model with a global intuitive eating factor and four specific factors best fit the data, which was temporally stable across three weeks. This model also had good fit in Study 3 and, across Studies 2 and 3, and was fully invariant and lacked measurement bias in terms of age, gender, and BMI. Associations between latent IES-3 factors and age, gender, and BMI were invariant across Studies 2 and 3. Composite reliability and validity (relationships with disordered eating, embodiment, body image, well-being, and distress; negligible relationship with impression management) of the retained model were also supported. The 12-item IES-3 demonstrates strong psychometric properties in U.S. community adults. Research is now needed using the IES-3 in other cultural contexts and social identity groups.

Eating disorder symptom dimensions and protective factors: A structural network analysis study

Eating Disorders (EDs) and related symptoms pose a substantial public health concern due to their widespread prevalence among both genders and associated negative outcomes, underscoring the need for effective preventive interventions. In this context, deepening our understanding of the interplay between ED symptoms and related protective factors appears crucial. Therefore, this study employed a structural network analysis approach considering both ED symptom dimensions (i.e., drive for thinness, bulimic symptoms, and body dissatisfaction) and related protective factors (i.e., body and functionality appreciation, intuitive eating, and self-esteem) to shed light on how these factors are interrelated. A community sample of 1391 individuals (34.4% men; Mage = 26.4 years) completed a socio-demographic schedule and self-report questionnaires. The network showed that the nodes with the highest positive expected influence were body and functionality appreciation, while those with the highest negative expected influence were eating for physical rather than emotional reasons and unconditional permission to eat (i.e., two components of intuitive eating). Crucially, the most relevant bridges between the conceptual communities "ED symptom dimensions" and "Protective factors" were the negative relations between (a) eating for physical rather than emotional reasons and bulimic symptoms, (b) unconditional permission to eat and drive for thinness, and (c) body appreciation and body dissatisfaction. Finally, age, gender, and body mass index did not moderate any edge in the network. The practical implications of these findings are discussed, especially in terms of preventive interventions for ED symptoms.

Psychometric network analysis of the Intuitive Eating Scale-2 in Chinese general adults

The Intuitive Eating Scale-2 (IES-2) is a measure of intuitive eating behaviors that has been extensively validated, with traditional latent variable modeling approaches, in youth and adults from many different populations, including college students in China. However, there is still a lack of research on the psychometric properties of the IES-2 in adults from the Chinese general population. Moreover, psychometric network analysis, as a complement to traditional latent variable modeling approaches, has not been used for examining the psychometric properties of the IES-2. Thus, the present study used a psychometric network approach to evaluate the psychometric properties of the IES-2 in Chinese adults from the general population. A sample of 700 Chinese general adults (50% women; Mage = 31.13 years, SD = 9.19) recruited online were included in the present study. Psychometric network analysis was performed. Exploratory graph analysis (EGA) identified four dimensions, which were well separated in the estimated network. The network structure showed excellent stability and metric measurement invariance (i.e., network loadings) across men and women. Furthermore, several items on the IES-2 were identified as key nodes in the network of the IES-2 that may be important for the development and maintenance of intuitive eating. For example, two items (i.e., "I trust my body to tell me when to eat," and "I trust my body to tell me when to stop eating") related to reliance on body cues were the most impactful nodes in the complete network. The findings of our study provide a greater understanding of the IES-2 from the perspective of network analysis and have implications for applications of intuitive eating interventions for general populations.

From Restriction to Intuition: Evaluating Intuitive Eating in a Sample of the General Population

Intuitive eating (IE) is a non-dieting approach that promotes listening to internal cues of hunger and satiety, rather than adhering to external dietary restrictions aimed at weight loss. However, the role of IE in dieting behaviors related to weight-loss approaches is still unclear. To address this issue, the aim of this study was to compare IE levels between dieting and non-dieting individuals, exploring the relationship between IE and dieting-related psychological and physical factors. A sample of 2059 females was recruited via social media and self-reported questionnaires were administered to measure IE, eating psychopathology, self-efficacy, and quality of life. Individuals with a history of dieting exhibited lower IE levels, a higher BMI, and a greater eating psychopathology, as well as a reduced self-efficacy and quality of life, compared to non-dieters. IE showed a protective effect against dieting behaviors, with higher IE levels being associated with a lower likelihood of dieting. Additionally, higher BMI and eating psychopathology were predictors of dieting. Promoting IE could represent a relevant clinical target strategy to address disordered eating and enhance overall well-being, underscoring the need for interventions that foster a healthier relationship with food and bodily internal sensations.

Relation between orthorexia nervosa and healthy orthorexia: A latent profile analysis

Orthorexic eating behaviors can be conceptualized as a bidimensional construct encompassing an orthorexia nervosa dimension (ON) and a healthy orthorexia dimension (HO). Although variable-centered studies showed that ON and HO are distinguishable orthorexic eating behaviors, the evidence of whether they can co-occur or be distinct in subgroups of individuals is still limited. The present study aimed to address previous person-centered studies' limitations by examining profiles of ON and HO among a convenience sample of 251 French-speaking Canadian adults (85.7% women; Mage = 33.56). Profile membership was examined as function of participants characteristics such as age, gender, body mass index, frequency of physical activity and sports and vegetarianism. The relation between profile membership, intuitive eating and disordered eating attitudes and behaviors was also assessed. Latent profile analysis (LPA) were used to estimate profiles of ON and HO. Results from LPA did not provide support for the distinguishability of ON and HO. Indeed, they revealed the presence of two profiles showing co-occurring levels of ON and HO that only differed quantitatively: low (68.9% of the sample; low levels of ON and HO) or moderate orthorexic eating behaviors (31.1%; moderate levels of ON and HO). Participants who declared being vegetarian and being more frequently involved in physical activities and sports were more likely to belong to the moderate orthorexic eating behaviors' profile. Finally, participants from the moderate orthorexic eating behaviors' profile showed higher levels of disordered eating attitudes and behaviors, whereas those from the low orthorexic eating behaviors' profile showed higher levels of intuitive eating. Findings from the present study question the distinguishability of ON and HO dimensions. They also suggest that, similarly to ON, HO is also related to higher eating and lifestyle preoccupations.

Translation and validation of a Chinese version of the Appearance Schemas Inventory-Revised in Chinese adults

The current study translated the Appearance Schemas Inventory-Revised (ASI-R) into Chinese (Mandarin) and examined its psychometric properties in Chinese adult women and men. Sample 1 included 400 women and 400 men to examine the factor structure of the ASI-R with exploratory factor analysis (EFA). Sample 2 involved 300 women and 300 men, and the EFA-derived factor structures in Sample 1 of the ASI-R were examined with exploratory structural equation modeling (ESEM), bifactor ESEM (B-ESEM), and bifactor ESEM with correlated uniqueness for negatively worded items (B-ESEM-CU) for both women and men. Results of the EFA identified a 4-factor model in women and a 2-factor model in men. The B-ESEM-CU consistently showed the best model fit. In the B-ESEM-CU, the general factor was well-defined, but the specific factors were not, supporting the use of the global factor to conceptualize the ASI-R for Chinese women and men. Evidence of adequate internal consistency, test-retest reliability, and construct validity of the global factor of the ASI-R was suggested in both women and men. Findings suggest the ASI-R is a useful instrument to measure body image investment in Chinese women and men, specifically using the B-ESEM-CU to understand the dimensionality of the ASI-R.

Challenges and opportunities for conceptualizing intuitive eating in autistic people

Although intuitive eating (IE) has become an increasingly adopted intervention target, current conceptualisations of IE have yet to pivot away from (neuro)normative physiology and phenomenology. Autistic individuals commonly report disordered eating behaviours and/or poorer well-being but appear to benefit from adaptive interventions using an affirmative approach. This article uses autism as a case example to summarise challenges related to IE's prevailing conceptualisation, before proposing how future research and current practice can be extended to the autistic population. Scholars are encouraged to evaluate the full 10-principal IE framework while utilising a participatory-led approach. We argue that research using a mixed methods design is urgently needed to comprehensively explore the (re)conceptualisation of IE in autistic people. While IE shows promise for producing positive outcomes in the autistic population, we discuss the potential challenges for research and practice due to its current emphasis on accurate interoception, emotional awareness and processing, and executive functioning. This suggests the need for research and practice to integrate autistic needs and experiences into future developments with an affirmative approach. Public Significance: IE is an effective intervention for reducing disordered eating behaviours. Autistic individuals commonly present disordered eating behaviours and have unique nutritional needs which often require intervention. However, there is limited understanding of IE among the autistic population. Research-informed definitions involving autistic perspectives will support translating the IE framework to this underrepresented population.

The Intuitive Eating Scale-2 Adapted for Mexican Pregnant Women: Psychometric Properties and Influence of Sociodemographic Variables

A weight-inclusive approach to health involves the promotion of intuitive eating, i.e., the individual's ability to be aware of their physiological hunger and satiety cues to determine when and how much to eat, while paying attention to how certain foods affect their body. The second version of the Intuitive Eating Scale (IES-2) evaluates four interrelated traits of intuitive eating: Unconditional Permission to Eat (UPE), Eating for Physical rather than emotional Reasons (EPR), Reliance on internal Hunger/Satiety Cues (RHSC), and Body-Food Choice Congruence (BFCC). In this study, our aim was to evaluate the psychometric properties of a Mexican Spanish adaptation of the IES-2 for pregnant women and examine the relationship between intuitive eating traits and maternal sociodemographic characteristics. A sample of 514 pregnant women answered our IES-2 adaptation and a sociodemographic questionnaire. We determined the quality, validity, and reliability of our adaptation through descriptive measures, frequency distributions, intra-class correlations, and extreme answer group comparison for each item, eliminating those with weak technical properties. We then performed an exploratory principal component analysis and a confirmatory factor analysis. Last, we analyzed the association between intuitive eating and maternal sociodemographic and reproductive variables through correlation tests and multivariable linear regressions. Psychometric tests confirmed the validity and reliability of our IES-2 adaptation, which comprised 18 out of the 23 original items. Notably, both the exploratory and confirmatory factor analyses yielded not four but five factors, due to the EPR subscale splitting in two (the "emotional" and "physical" components of EPR). We attribute this novel finding to the emotional manifestations that naturally accompany pregnancy, which may incline pregnant women to base their eating behaviors more on the emotional than the physical component that would otherwise dominate their EPR trait. Further research is also needed about the UPE subscale during pregnancy, due to item removal and subtle changes in meaning. Finally, the influence of sociodemographic variables on the IES-2 score was extremely low, suggesting that other variables, possibly of a psychological nature, may have greater influence on a pregnant woman's intuitive eating.

A guide to exploratory structural equation modeling (ESEM) and bifactor-ESEM in body image research

Traditionally, assessments of factor validity of body image instruments have relied on exploratory or confirmatory factor analysis. However, the emergence of exploratory structural equation modeling (ESEM), a resurgence of interest in bifactor models, and the ability to combine both models (bifactor-ESEM) is beginning to shape the future of body image research. For these analytic approaches to truly advance body image research, scholars will need to have a deep understanding of their use and application. To facilitate such understanding, we describe ESEM and bifactor-ESEM models for body image researchers and provide them with the tools they need to apply these methods in their own work. Specifically, we provide an overview of ESEM and bifactor-ESEM models, and describe their broad applicability to body image research. Next, we describe how ESEM and bifactor models can be used and, using an existing dataset of responses to the Acceptance of Cosmetic Surgery Scale, demonstrate how ESEM and bifactor-ESEM models can be deployed. To facilitate wider application of these ideas, we provide our Mplus syntax (inputs) in Supplementary Materials. Through this manuscript, we hope to assist researchers to better understand the strengths ESEM and bifactor models, and to use these approaches in their own work.

Psychometric properties of a Romanian translation of the Acceptance of Cosmetic Surgery Scale (ACSS): An examination using bifactor exploratory structural equation modelling

The Acceptance of Cosmetic Surgery Scale (ACSS; Henderson-King & Henderson-King, 2005) is a widely used measure for the assessment of attitudes toward cosmetic surgery. Here, we examined the psychometrics of a novel Romanian translation of the ACSS. A total of 1275 Romanian adults (889 women, 386 men) completed the ACSS alongside additional, related measures. Exploratory factor analysis (EFA) with a first split-half subsample supported extraction of the original 3-factor model consisting of Intrapersonal, Social, and Consider dimensions. In a second split-half subsample, we found that a 3-factor bifactor exploratory structural equation model (B-ESEM) had superior fit compared to all alternative models that were tested. This B-ESEM representation had well-defined G-factor with adequate composite reliability, and its S-factors were also generally well-defined. Across subsamples, the optimal model showed strong or partial strong invariance across gender, with women having significantly higher latent means on the Consider factor relative to men. Evidence of convergent validity was also generally good in women, especially for the G-factor of the ACSS, but was attenuated in men. Overall, these findings indicate that the Romanian version of the ACSS has adequate psychometric properties. We also encourage scholars to consider B-ESEM representations of the ACSS in other national settings.

Psychometric properties of the Arabic version of the Intuitive Eating Scale-2 (IES-2) in a sample of community adults

BACKGROUND

There is a growing attention on intuitive eating (IE) styles in the Western world that has not yet reached Arab countries, which is likely due to the lack of psychometrically sound measures of the IE construct for Arabic-speaking people. The current study aims to examine the psychometric properties of an Arabic translation of the most widely used measure of IE-the Intuitive Eating Scale-2 (IES-2), in an Arabic-speaking community population from Lebanon.

METHODS

Two samples of Arabic-speaking community adults from Lebanon (sample 1: n = 359, 59.9% females, age 22.75 ± 7.04 years; sample 2: n = 444, 72.7% females, age 27.25 ± 9.53 years) were recruited through online convenience sampling. The translation and back-translation method was applied to the IES-2 for linguistic validation. Factorial validity was investigated using an Exploratory Factor Analysis & Confirmatory Factor Analysis strategy. Composite reliability and sex invariance were examined. We also tested convergent and criterion-related validity through correlations with other theoretically plausible constructs.

RESULTS

Nine out of the original 23 items were removed because they either loaded below 0.40 and/or cross-loaded too highly on multiple factors. This resulted in four domains (Unconditional Permission to Eat, Eating for Physical Rather than Emotional Reasons, Reliance on Hunger and Satiety Cues, and Body-Food Choice Congruence) and 14 items retained. Internal reliability estimates were excellent, with McDonald's ω values ranging from 0.828 to 0.923 for the four factors. Multigroup analysis established configural, thresholds, metric, scalar, strict invariance across gender. Finally, higher IES-2 total scores were significantly correlated with lower body dissatisfaction scores and more positive eating attitudes, thus attesting to convergent and criterion-related validity of the scale.

CONCLUSIONS

The current findings provide preliminary evidence for the appropriate psychometric qualities of the Arabic 14-item, four-factor structure IES-2; thereby supporting its use at least among Arabic-speaking community adults.

Psychometric properties of a Greek translation of the Intuitive Eating Scale-2 (IES-2) in adults from Cyprus

The construct of intuitive eating is commonly assessed using the 23-item, 4-factor Intuitive Eating Scale-2 (IES-2; Tylka & Kroon Van Diest, 2013). In this study, we assessed the psychometric properties of a novel Greek translation of the IES-2 in adults from Cyprus. In Study 1 (N = 626), an exploratory factor analysis indicated that the IES-2 should be conceptualized as consisting of six factors that showed complete invariance across women and men. Study 2 (N = 793), using exploratory structural equation modelling (ESEM) and beifactor analysis (B-ESEM), indicated that the 6-factor B-ESEM model had adequate fit and evidenced complete invariance across sex once the correlated uniqueness of negatively worded IES-2 items was accounted for. This final model evidenced adequate composite reliability, and a global G-factor evidenced adequate convergent, concurrent, and discriminant validity. In contrast, the IES-2 S-factors showed more equivocal patterns of validity, with some S-factors showing less-than-adequate associations with body image variables, self-esteem, symptoms of disordered eating, and fruit and vegetable intake. In general, these results provide satisfactory evidence of the psychometric properties of the Greek IES-2 in adults from Cyprus, but also suggest that models of IES-2 scores may vary across national or cultural contexts.

The intuitive eating scale-2: re-evaluating its factor structure using a bifactor exploratory structural equation modelling framework

PURPOSE

Previous studies examining the appropriateness of the 4-factor model of intuitive eating scale-2 (IES-2) scores have returned equivocal results, which may reflect methodological limitations in the way IES-2 scores are modelled. Here, we applied a bifactor-exploratory structural equation modelling (B-ESEM) framework to better understand IES-2 multidimensionality.

METHODS

A total of 603 participants from the United States completed the IES-2, alongside measures of body appreciation, body acceptance from others, and self-esteem. Our analyses compared the fit of various hypothesised models of IES-2 scores.

RESULTS

Models of IES-2 scores based on confirmatory factor analysis (CFA) uniformly showed poor fit. ESEM models showed superior fit to CFA representations and a B-ESEM model showed improved fit over higher-order CFA and B-CFA representations of IES-2 scores. The optimal model was a B-ESEM model that accounted for, through correlated uniqueness (CU), the methodological artefact introduced by negatively-worded IES-2 items. This B-ESEM-CU model was fully invariant across gender and showed adequate construct validity.

CONCLUSION

The B-ESEM-CU framework appears well-suited to understand the multidimensionality of IES-2 scores. A model of IES-2 scores that yields a reliable latent indicator of global intuitive eating while allowing for simultaneous consideration of additional specific factors will likely provide more accurate accounting of the nature and outcomes of intuitive eating.

LEVEL OF EVIDENCE

Level III, cohort study.

Polish Adaptation and Validation of the Intuitive (IES-2) and Mindful (MES) Eating Scales—The Relationship of the Concepts with Healthy and Unhealthy Food Intake (a Cross-Sectional Study)

Intuitive (IE) and mindful (ME) eating share internally focused eating, yet previous studies have shown that these concepts are not strongly correlated, which suggests that they might be differently related to food intake. The study aimed to adapt the original Intuitive (IES-2) and Mindful (MES) Eating Scales to the Polish language, to test their psychometric parameters and, further, to examine associations of IE and ME with an intake of selected food groups, i.e., healthy foods (fresh and processed vegetables, fresh fruit) and unhealthy foods (sweets, salty snacks). A cross-sectional study was conducted in 2020 in a group of 1000 Polish adults (500 women and 500 men) aged 18–65 (mean age = 41.3 ± 13.6 years). The factor structure was assessed with exploratory (EFA) and confirmatory (CFA) factor analysis as well as structural equation modeling (SEM). Measurement invariance across gender was assessed with multiple-group analysis. Internal consistency and discriminant validity of the two scales was tested. Spearman’s correlation coefficient was used to examine the correlation between IES-2 and MES subscales with food intake. A 4-factor, 16-item structure was confirmed for IES-2, while EFA and CFA revealed a 3-factor, 17-item structure of MES. Both scales demonstrated adequate internal consistency and discriminant validity. Full metric and partial scalar invariance were found for IES-2, while MES proved partial invariances. “Awareness” (MES) and “Body–Food Choice Congruence” (IES-2) positively correlated with intake of healthy foods and negatively with the intake of unhealthy ones. “Eating For Physical Rather Than Emotional Reasons” (IES-2) and “Act with awareness” (MES) favored lower intake of unhealthy foods, whereas “Unconditional Permission to Eat” and “Reliance on Hunger and Satiety Cues” (IES-2) showed an inverse relationship. A greater score in “Acceptance” (MES) was conducive to lower intake of all foods except sweets. The results confirmed that adapted versions of the IES-2 and MES are valid and reliable measures to assess IE and ME among Polish adults. Different IE and ME domains may similarly explain intake of healthy and unhealthy foods, yet within a single eating style, individual domains might have the opposite effect. Future studies should confirm our findings with the inclusion of mediating factors, such as other eating styles, childhood experiences, dieting, etc.