In Study 2, we tested the fit of the 3-factor solution that resulted from Study 1 in an independent undergraduate student sample. We included measures of ED psychopathology and other clinical syndromes (i.e., depression, self-injury, anxiety, and alcohol use). We hypothesized that, when controlling for sex, BMI, and the two other RES subscales (due to their moderate inter-correlations), (a) negative mood-cued exercise would be positively associated with measures of psychopathology but not ED-specific psychopathology; (b) eating and body image-cued exercise would be positively associated with ED psychopathology; and (c) positive mood-cued exercise would be negatively associated with psychopathology.
The local institutional review board approved this study. Undergraduate students from a Northern Plains university participated in an online study (hosted on Qualtrics) for credit toward course requirements advertised as a survey study about exercise, eating behavior, and mental health.
Participants were 300 undergraduates. Their mean (SD) age was 19.8 (1.9) years, 73.4% reported female sex, and 72.9% reported identifying as women. Their mean (SD) BMI based on self-reported height and weight was 24.4 (4.6) kg/m2. The majority identified as non-Hispanic, White (84.9%), with fewer identified as Hispanic (9.9%), Asian (2.3%), Black (0.7%), or other/mixed (2.3%).
RES. The 25 RES items retained from Study 1 comprised the version of the RES used in this study.
Eating Disorder Examination – Questionnaire (EDE-Q). The EDE-Q (Fairburn & Beglin, 1994) is a 28-item self-report questionnaire that assesses the frequency of eating behaviors over the prior 28-days and provides indications of eating psychopathology on four subscales (Dietary Restraint [α = .87], Eating Concern [α = .88], Shape Concern [α = .94], and Weight Concern [α = .90]), which are averaged to form a Global Score (α = .96).
Eating Pathology Symptoms Inventory (ESPI). The EPSI (Forbush et al., 2013) is a 45-item self-report questionnaire assessing eight subscales: Body Dissatisfaction (α = .91); Binge Eating (α = .86); Cognitive Restraint (α = .75); Purging (α = .86); Restricting (α = .85); Excessive Exercise (α = .91); Negative Attitudes Toward Obesity (α = .88); and Muscle Building (α = .82). Participants respond to each item using a 5-point scale from 0 (Never) to 4 (Often) describing how much each item characterizes their experiences, with higher scores indicating higher standing on the dimensions.
Clinical Impairment Assessment (CIA). The CIA (Bohn et al., 2008) is a 16-item self-report measure assessing psychosocial impairment due to ED symptoms over the prior 28 days. Participants rate the extent to which eating problems and weight and shape concerns have caused them impairment in various aspects of their life, with higher scores indicative of greater impairment. Cronbach’s alpha was .96.
Multidimensional Body-Self Relations Questionnaire (MBSRQ). The MBSRQ (Cash, 2000) is a 69-item self-report questionnaire that assesses body image disturbance on 10 subscales. Participants rate the extent to which they agree with statements about their appearance from 1 (Definitely disagree) to 5 (Definitely agree). The subscales are Appearance Evaluation (α = .91), Appearance Orientation (α = .84), Fitness Evaluation (α = .81); Fitness Orientation (α = .90); Health Evaluation (α = .70); Health Orientation (α = .76); Illness Orientation (α = .74); and the Body Area Satisfaction Scale (BASS; α = .87).
Center for Epidemiologic Studies Depression Scale-Revised (CESD-R). The CESD-R (Eaton et al., 2004) is a 20-item self-report measure of depression, based on the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (APA, 2000) criteria. Participants respond to questions asking about the frequency of symptoms of depression they have experienced over the prior week, ranging from 0 (Not at all) to 4 (A lot). Scores on the CESD-R range from 0-60, with higher scores indicating greater presence of depressive symptoms. Cronbach’s alpha was .95.
Alcohol Use Disorders Identification Test (AUDIT). The AUDIT (Saunders et al., 1993) is a 10-item measure assessing alcohol consumption, drinking behaviors, and alcohol-related problems. Items measure typical frequency, typical quantity per occasion, and heavy episodic drinking (six or more drinks per occasion) frequency. Participants respond to statements indicating the frequency that they have engaged in each statement, with response options coded from 0-4 and higher scores indicating more problems with alcohol. Cronbach’s alpha was .81.
State-Trait Inventory for Cognitive and Somatic Anxiety (STICSA). The STICSA (Ree et al., 2008) is a self-report measure assessing cognitive and somatic symptoms of anxiety as pertaining to one’s current feelings of anxiety (state) and one’s general, overall feelings of anxiety (trait). Participants rate each item on a 4-point scale, ranging from 1 (Not at all) to 4 (Very much so). Cronbach’s alpha was .94 for the total trait measure, which is what we used here.
Brief Experiential Avoidance Questionnaire (BEAQ). The BEAQ (Gámez et al., 2014) is a brief measure of the Multidimensional Experiential Avoidance Questionnaire (MEAQ). It is a 15-item self-report questionnaire assessing experiential avoidance. Each item is scored on a 6-point scale ranging from 1 (Strongly disagree) to 6 (Strongly agree). Higher scores are indicative of greater levels of experiential avoidance. Cronbach’s alpha was .87.
Inventory of Statements about Self-Injury (ISAS). The ISAS (Klonsky & Glenn, 2009) assesses lifetime frequency of non-suicidal self-injurious (NSSI) behaviors performed “intentionally (i.e., on purpose) and without suicidal intent (i.e., not for suicidal reasons).” The behaviors assessed include banging/hitting self, biting, burning, carving, cutting, wound picking, needle-sticking, pinching, hair-pulling, rubbing skin against rough surfaces, severe scratching, and swallowing chemicals. Participants were asked to estimate the number of times in their lives they have performed each behavior, which we dichotomized as ever present versus absent.
We conducted a confirmatory factor analysis (CFA) using Mplus (Version 8.3; Muthén & Muthén, 2017) to test the fit of the 3-factor solution using the MLR estimator. We assessed fit using the root mean square error of approximation (RMSEA; < .08 is fair; Brown & Cudeck, 1993), comparative fit index (CFI; > 0.95 is excellent; Hu & Bentler, 1999), Tucker-Lewis index (TLI; > 0.90 is acceptable; Bentler & Bonett, 1980), and the standardized root mean square residual (SRMR; < 0.06 is ideal; Hu & Bentler, 1999).
We calculated partial correlations between the RES scales and other study measures while controlling for the other RES scales and participant sex and BMI. We conducted independent samples t-tests to examine whether scores on each subscale differed by sex. Finally, we conducted a multiple linear regression to account for EDE-Q Global Score, a broad measure of ED psychopathology, using the RES scales, sex, and BMI to examine which, if any, RES scales were uniquely associated with this important indicator of ED psychopathology while accounting for their shared variance.
After freeing the covariances of similarly worded items, the solution fit well (c2(263) = 485.33, p < .001; RMSEA = .053 [95%CI: .046, .061]; CFI = 0.95; TLI = 0.94; SRMR = 0.05). The factors indicate the tendency to exercise in response to negative mood cues, in response to eating and body image cues, and in response to positive mood cues (Figure 2).
[Figure 2 here]
Male participants scored higher on the negative mood cue subscale (44.62 ± 25.61) than female participants (34.51 ± 27.01; t(294) = -2.90, p = .004, d = 0.38), and they scored higher on the positive mood cue subscale (65.03 ± 28.43) than female participants (56.83 ± 30.02; t(294) = -2.12, p = .035, d = 0.28). In contrast, female participants scored higher on the eating and body image cued subscale (53.60 ± 26.95) than male participants (44.20 ± 25.12; t(294) = 2.71, p = .007, d = -0.36).
Results of correlations between RES scales and other measures are displayed in Tables 3 and 4. The results of the multiple linear regression on the EDE-Q Global Score using all three RES scales indicated that, while controlling for sex and BMI, only the exercising in response to eating and body image cues factor was uniquely associated with EDE-Q Global Score (B = 0.51, t = 7.83, p < .001).
[Table 3 here]
[Table 4 here]
The Tendency to Exercise in Response to Negative Mood Cues
Exercising in response to negative mood cues was positively associated with the EDE-Q item assessing driven exercise, the EPSI excessive exercise and muscle building subscales, and the MBSRQ fitness and health orientation subscales. It was not associated with ED psychopathology subscales that do not assess exercise (e.g., dietary restraint, shape concern, restriction, impairment). The negative mood subscale was also not associated with any non-ED psychopathology measures.
The Tendency to Exercise in Response to Eating and Body Image Cues
Exercising in response to eating and body image cues was associated with higher scores on the EDE-Q dietary restraint and eating concern subscales; EPSI restriction, cognitive restraint, and purging subscales; the presence of objectively large binge-eating episodes and purging as measured by the EDE-Q; and ED-related impairment as measured by the CIA. It was also positively associated with concerns regarding shape and weight (EDE-Q Shape Concern and Weight Concern) and negative attitudes toward obesity (EPSI Negative Attitudes toward Obesity). Higher scores on this dimension were positively associated with body dissatisfaction (EPSI Body Dissatisfaction) and appearance orientation (MBSRQ Appearance Orientation) and negatively associated with body image satisfaction (MBSRQ Appearance Evaluation, BASS) and health evaluation (MBSRQ Health Evaluation). Exercising in response to eating and body image cues was associated with greater endorsement of driven and excessive exercise (EDE-Q Driven Exercise and EPSI Excessive Exercise) and worse depression (CESD-R) and experiential avoidance (BEAQ). Finally, this dimension was not associated with binge eating measured by the EPSI, objectively large overeating episodes as measured by the EDE-Q, muscle building, fitness evaluation and orientation, health orientation, illness orientation, or depression, presence of self-injury, anxiety, and alcohol use.
The Tendency to Exercise in Response to Positive Mood Cues
No significant correlations were found between the tendency to exercise in response to positive mood cues and ED psychopathology or measures of other psychopathology. Exercising in response to positive mood cues was negatively associated with EPSI body dissatisfaction and positively associated with MBSRQ body satisfaction and appearance evaluation. It was also positively associated with EPSI excessive exercise and MBSRQ health and fitness evaluation and orientation. Further, the positive correlation between the RES Positive Mood subscale and MBSRQ Illness Orientation subscale suggests that exercising in response to positive mood is associated with increased alertness about, or reactivity to, being sick. An additional negative association was found between RES Positive Mood and BEAQ experiential avoidance. Exercising in response to positive mood cues was not associated with anxiety, depression, alcohol use problems, self-injury, age, or BMI.
Study 2 Discussion
The results of Study 2 provided support for the three-factor structure identified in Study 1, albeit with minor modifications to address correlated errors between similarly worded items. Convergent and discriminant evidence indicates that the negative mood cue subscale measures the tendency to engage in exercise in response to negative mood cues that are not specific to ED psychopathology, but are associated with other aspects of mental health, generally involving low mood and mood regulation. However, the negative mood factor did not demonstrate many associations with psychopathology, contrary to our prediction. Conversely, the eating and body image cues subscale appears to measure the tendency to engage in exercise that is related to ED psychopathology. Finally, the positive mood cue subscale appears to measure exercise that is generally associated with favorable mental health and not associated with psychopathology, ED or otherwise. Importantly, all three subscales demonstrate unique relations with the EPSI Excessive Exercise scale, and both the negative mood cue and the eating and body image cue subscales had unique relations with the EDE-Q question assessing driven exercise. Differences by sex indicated that male participants report stronger tendencies to exercise in response to mood cues but weaker tendencies to exercise in response to eating and body image cues than female participants, the latter of which is consistent with sex differences commonly observed on dimensions of ED psychopathology.