1. Introduction
Eating disorders (EDs) are severe mental illnesses characterized by disturbances in eating behaviors and body image [
1]. Traditionally, research on EDs and their key risk factors—body image disturbances—was mainly conducted among women [
2,
3,
4]. However, there has been ample evidence showing that EDs and body image disturbances increasingly occur in men, and the presentations of EDs and body image disturbances among men are often distinct to those observed in women [
5]. Specifically, according to the previous literature [
3,
5,
6], EDs and body image disturbances among women are typically thinness-oriented (i.e., drive for thinness), while EDs and body image disturbances among men are typically muscularity-oriented (i.e., drive for muscularity).
The majority of the existing measures that are widely used for assessing ED symptomatology and body image disturbances are thinness-focused, such as the Eating Attitude Test [
7], the Eating Disorder Examination [
8] and the Eating Disorder Inventory [
9]. Thus, the measures are not sensitive enough to capture the core features of disordered eating or body image disturbances among men [
5].
To fill this gap, Murray et al. [
6] developed and validated the Muscularity-Oriented Eating Test (MOET) with a sample of 511 undergraduate men in the US. Specifically, the MOET contains 15 items that are rated on a 5-point Likert-type scale from 0 (“never true”) to 4 (“always true”). In the work of Murray et al. [
6], the MOET showed a unidimensional structure, high internal consistency (omega = 0.92~0.93), high test-retest correlation (
r = 0.75) and construct validity, as indicated by large correlations between the MOET scores and theoretically closely related measures (e.g., drive for muscularity) but small correlations between the MOET scores and theoretically weak or unrelated measures (e.g., socially desirable response). Currently, the MOET has been translated into Spanish, and the Spanish version replicated the unidimensional structure and showed good psychometric properties in a sample of Argentinian college men [
10].
To date, research on EDs or body image disturbances among men is mainly conducted in Western societies among adolescents or young adults of Caucasian ethnicity [
2]. However, there has been a rising trend of ED prevalence in Asian countries, including China [
11,
12], and more attention has been called to EDs in Chinese men [
13]. Thus, it is imperative and significant to conduct more research on EDs in Chinese male populations for exploring whether there are unique clinical manifestations, risk factors and health consequences of EDs in Chinese men.
Furthermore, as body image is a key contributing factor of EDs [
14], it is also important to assess male-specific body image disturbances to explore the etiology of EDs among men. However, different from women and girls, the major body image concern among men and boys is drive for muscularity [
15,
16,
17], which refers to an individual’s desire to achieve an ideal muscular body [
15]. Previous studies have shown that drive for muscularity is a significant risk factor for EDs among men [
3,
18,
19]. Furthermore, drive for muscularity is also a significant risk factor or characteristic of muscle dysmorphia (MD) [
20,
21,
22]. Specifically, as a subtype of body dysmorphic disorder, muscle dysmorphia (MD) represents the pathological extreme pursuit of muscularity and is characterized by a pervasive belief or fear around insufficient muscularity [
23,
24]. Muscle dysmorphia is mostly researched among men, and it leads to considerable functional impairment [
25].
However, to the best our knowledge, there have been no such measures available in Chinese for assessing male-specific body image disturbances or muscle dysmorphia. To bridge this gap, another two widely used measures assessing male-specific body image disturbances were also chosen to be translated and validated in the current study: the Drive for Muscularity Scale (DMS) [
15] and the Muscle Dysmorphic Disorder Inventory (MDDI) [
26].
Specifically, the DMS is a 15-item self-report questionnaire rated on a 6-point Likert-type scale with responses from 1 (“always”) to 6 (“never”), which has two subscales: the muscle-oriented body image subscale (MBI, or the muscularity attitudes subscale; 7 items) and the muscle-oriented behavior subscale (MB, or the muscularity behavior subscale; 8 items) [
15]. All items are reverse-coded, in which the total score (or mean score) of the 15 items then represents an individual’s overall drive for muscularity. The higher the total score, the stronger the attitudes and behaviors of drive for muscularity. Currently, the DMS has been translated into a number of different languages and shown adequate reliability and validity, including Romanian [
27], Spanish [
28,
29], French [
30], Turkish [
31], Portuguese [
32] and Japanese [
33].
The MDDI [
26] contains 13 items that comprise three subscales: drive for size (DFS, 5 items), appearance intolerance (AI, 4 items) and functional impairment (FI, 4 items). The MDDI is rated on a 5-point Likert-type scale with responses from 1 (“never”) to 5 (“always”). A total score can be derived by the sum of all items or all subscales. Higher total scores indicate more symptoms of muscle dysmorphia. The MDDI has also been translated into a number of different languages and demonstrated good psychometric properties in samples from different countries, including Portuguese [
34], Italian [
35], German [
25], Turkish [
36] and Spanish [
37].
Overall, the current study aimed to translate and validate three measures (i.e., the MOET, DMS and MDDI) to facilitate future research on EDs and body image disturbances among Chinese men. We hypothesized that (1) the MOET would have a unidimensional factor structure, the DMS would have a two-factor structure, and the MDDI would have a three-factor structure; (2) the three measures would have adequate reliably as indicated by internal consistency; (3) the total scores of the three measures would be closely related to each other; and (4) the total scores of the three measures would be positively related to traditional eating disorder symptomology, psychological impairment, psychological distress and thinness-oriented body dissatisfaction.
4. Discussion
The need to further study male EDs and body image disturbances among Chinese men has been made clear [
13]. However, due to the lack of validated instruments assessing eating and body image disturbances among Chinese men, limited research about these topics is possible at this time in China. Thus, the current study aimed to translate three measures (i.e., the MOET, DMS and MDDI) that specifically assess eating and body image disturbances among men and examine the psychometric properties of the Chinese translations of the three measures. The results showed that all measures presented good psychometric properties with both a sample of male university students and a sample of general male adults.
Specifically, in line with our hypotheses, the respective one-factor structure [
6], two-factor structure [
15] and three-factor structure [
26] of the MOET, DMS and MDDI were successfully confirmed via CFA in the current study. This indicates that the structures of the scales are stable across different cultures, especially considering that the factor structures of the DMS and MDDI have been successfully replicated in a number of samples from different countries. Thus, future researchers may consider conducting cross-cultural measurement invariance tests (e.g., [
59]) for the three measures to explore whether these measures can be used for cross-cultural comparisons in disordered eating and body image disturbances among men, which can greatly forward our understanding of the cultural differences in these areas.
The McDonald’s omega values for the MOET, DMS subscales and MDDI subscales were acceptable in the current two samples, suggesting that the scores of the three measures had adequate internal consistency reliability, which is in line with previous validation studies (e.g., [
6,
15,
26]). In the present work, as hypothesized, the scores of the three measures were found to be significantly and positively related to each other. These large inter-correlational findings provide evidence for the convergent validity of the three measures, since all three constructs being measured (i.e., muscularity-oriented disordered eating, drive for muscularity and muscle dysmorphic disorder symptoms) are focused on muscularity.
We also found that the total scores of the three measures were closely related to traditional eating disorder symptomology. These findings are also consistent with the previous literature [
6,
10]. As muscularity concerns in men include not only muscularity but also leanness [
5], it is not surprising to find large correlations between the scores of the three measures and traditional eating disorder symptomology, which is thinness-oriented. Furthermore, the close relationships between the scores of the three measures and psychosocial impairment secondary to eating disorder symptomology suggest the potential negative effects from muscularity-oriented disordered eating and body image disturbances on men’s quality of life. Together, with the medium correlations between the total scores of the three measures and psychological distress, these correlational findings warrant interventions for EDs and body image disturbances among Chinese men.
The results also showed that thinness-oriented body dissatisfaction, as measured by the EDI-BD, had small to medium associations with the scores of the three measures. These findings are not surprising, since the EDI-BD focuses on body weight and shape dissatisfaction due to body fat [
49], while the three measures focus on muscularity. Moreover, the scores of the three measures contributed a significant amount of unique variance to each criterion variable, indicating the good incremental validity of the three measures.
Finally, we found that the subscale scores of the DMS and MDDI were significantly higher in general adult men than university students, indicating that Chinese general adult men may have more muscularity-oriented body image disturbances. Except for the sampling differences in recruiting the two samples (paper and pencil in university students vs. online in general adults), the large differences in professional status may also help explain the score differences in the DMS and MDDI. Specifically, different from Chinese university students who generally live in university dormitories and rely on the monthly financial support from their parents to live (called “monthly living fees”) [
60], the majority of the general adults in the current study were employed and had stable income. Thus, general adults should have more time and money to get involved in activities to strengthen their muscles.
The current work is not free from limitations. First, because the sample sizes were only enough for us to run CFAs, we did not conduct exploratory factor analysis by splitting the samples as recommended in validating body image related measures [
61]. Thus, the current study only confirmed the original factor structures shown in the previous literature, and future studies with larger sample sizes are needed to explore whether there are different factor structures in the three measures in the Chinese context. However, it should also be noted that as the original factor structures of the DMS and MDDI had been replicated in a wide variety of populations, and a recent validation of MOET also replicated the original single-factor structure [
10], we chose to run CFAs only for confirming the original factor structures. Second, our study was limited to Chinese adult men. Thus, the findings cannot be generalized to Chinese women, adolescent boys or clinical populations (i.e., patients with eating disorders or muscle dysmorphia). Third, the invariance tests by sample type were not conducted, as certain important factors, such as sexual orientation [
62], were not included because we did not collect such information. However, future studies should be conducted to check whether these measures can be used to make group comparisons. Fourth, the test-retest reliability of the measures was not assessed. Thus, the test-retest reliability of the three measures remains unknown. Finally, as a common issue in survey research, socially desirable responding [
63] might have affected the scores obtained in the scales, so future studies may test whether socially desirable responding is an important issue by including an instrument to assess socially desirable response tendencies (e.g., [
64]). Future researchers are highly encouraged to conduct research by considering the limitations of the current work.