Testing "Feeling Fat" as a Mediator of the Longitudinal Relationship Between Negative Emotions and Eating Disorder Behaviors.

OBJECTIVE: Negative affect is central to eating disorder maintenance models; identifying mechanisms underlying this link may inform specific treatment targets. The current study evaluated which emotions (i.e., distress, fear, and moral emotions) were most strongly linked to feeling fat and tested feeling fat as a longitudinal mediator of the relationship between these emotions and restricting or binge eating (https://osf.io/3d5cq/). METHOD: Community adults (N = 714, M[SD] age = 41.5[13.7], 84.6% female, 85.9% white) provided data at baseline, 3-month, and 6-month follow-up. Relative weights analysis examined which emotion categories exhibited the strongest longitudinal relationships with feeling fat. Cross-lagged panel models tested feeling fat as a mediator of the relationship between emotions and eating disorder behaviors. RESULTS: Distress and moral emotions were the strongest emotional predictors of feeling fat. Feeling fat predicted binge eating (p's < 0.001), but not restricting (p's ≥ 0.832), in random effects cross-lagged panel models. Feeling fat partially mediated the longitudinal relationship between distress and binge eating (p = 0.044); however, this effect became nonsignificant after adjusting for BMI (p = 0.354). Feeling fat did not mediate relationships between moral emotions and binge eating or between either distress or moral emotions and restricting (p's ≥ 0.638). DISCUSSION: Feeling fat was associated with binge eating, not restricting, highlighting the importance of specificity in maintenance models. Because the mediating effect of feeling fat was accounted for by body size, factors associated with body size, such as internalized weight stigma, may be more relevant mediators of the relationship between negative emotions and eating disorder behaviors. Future research on feeling fat should adjust for body size.

Subtypes of exercise are differentially associated with baseline eating disorder pathology and treatment outcome among individuals with bulimia nervosa.

OBJECTIVE: Individuals with bulimia nervosa (BN) engage in both maladaptive (i.e., compulsive and/or compensatory) and adaptive exercise (e.g., for enjoyment). No research has examined whether those who engage in adaptive, compulsive, and/or compensatory exercise exhibit differences in BN pathology or treatment outcome compared to those not engaging in exercise, limiting intervention efficacy. METHOD: We examined associations of baseline exercise engagement with baseline and posttreatment BN pathology among 106 treatment-seeking adults (Mage = 37.4, SDage = 12.95, 87.74% female, 68.87% White) enrolled across four clinical trials of outpatient enhanced cognitive behavioral therapy for BN (range: 12-16 sessions). Analysis of covariances examined associations between baseline exercise type and baseline/posttreatment global eating pathology, dietary restraint, loss-of-control (LOC) eating, and purging frequency. RESULTS: Those engaging in only adaptive exercise reported lower global eating pathology compared to those engaging in compulsive-only exercise (Est = -1.493, p = .014, Mdiff = -.97) while those engaging in baseline compulsive exercise reported less LOC eating compared to those not engaging in exercise (Est = -22.42, p = .012, Mdiff = -12.50). Baseline engagement in compulsive-only exercise was associated with lower posttreatment global eating pathology compared to baseline engagement in no exercise (Est = -.856, p = .023, Mdiff = -.64) and both compulsive and compensatory exercise (Est = .895, p = .026, Mdiff = -1.08). DISCUSSION: Those engaging in compulsive, compensatory, adaptive, and no exercise exhibit different patterns and severity of BN pathology. Future research is needed to position treatments to intervene on maladaptive, while still promoting adaptive, exercise. PUBLIC SIGNIFICANCE STATEMENT: No research to date has examined whether those who engage in adaptive, compulsive, and/or compensatory exercise exhibit differences in BN pathology or treatment outcome compared to those not engaging in exercise, limiting targeted intervention efforts. We found that those engaging in compulsive, compensatory, and adaptive exercise exhibit different patterns of BN pathology and that adaptive exercise engagement was related to lower cognitive eating disorder symptoms at baseline.

Examining the placement of atypical anorexia nervosa in the eating disorder diagnostic hierarchy relative to bulimia nervosa and binge-eating disorder.

OBJECTIVE: Some individuals meet the criteria for atypical anorexia nervosa and another eating disorder simultaneously. The current study evaluated whether allowing a diagnosis of atypical anorexia nervosa to supersede a diagnosis of bulimia nervosa (BN) or binge-eating disorder (BED) provided additional information on psychological functioning. METHODS: Archival data from 650 university students (87.7% female, 69.4% white) who met Eating Disorder Diagnostic Survey for DSM-5 eating disorder criteria and completed questionnaires assessing quality of life, eating disorder-related impairment, and/or eating pathology at a single time point. Separate regression models used diagnostic category to predict quality of life and impairment. Two diagnostic schemes were used: the DSM-5 diagnostic scheme and an alternative scheme where atypical anorexia nervosa superseded all diagnoses except anorexia nervosa. Model fit was compared using the Davidson-Mackinnon J test. Analyses were pre-registered (https://osf.io/2ejcd). RESULTS: Allowing an atypical anorexia nervosa diagnosis to supersede a BN or BED diagnosis provided better fit to the data for eating disorder-related impairment (p = .02; n = 271), but not physical, psychological, or social quality of life (p's ≥ .33; n = 306). Allowing an atypical anorexia nervosa diagnosis to supersede a BN or BED diagnosis provided a better fit in cross-sectional models predicting purging (p = .02; n = 638), but not body dissatisfaction, binge eating, restricting, or excessive exercise (p's ≥ .08; n's = 633-647). DISCUSSION: The current data support retaining the DSM-5 diagnostic scheme. More longitudinal work is needed to understand the predictive validity of the atypical anorexia nervosa diagnosis. PUBLIC SIGNIFICANCE: The current study examined how changes to the diagnostic categories for eating disorders may change how diagnoses are associated with quality of life and impairment. Overall, findings suggest that the diagnostic hierarchy should be maintained.

The role of sexual assault history and PTSD in responses to food intake among women with bulimic-spectrum eating disorders.

Sexual abuse or assault (SA) history is associated with eating disorder severity and psychiatric comorbidity, including post-traumatic stress disorder (PTSD). Beyond persistent alterations in mood and cognitions characterizing PTSD, PTSD due to SA may contribute to greater increases in negative affect and body image concerns following food intake in bulimic syndromes (BN-S). To test this, participants (n = 172) with BN-S who reported PTSD due to SA, PTSD due to other forms of trauma, or neither completed clinical interviews and momentary reports of negative affect and shape/weight preoccupation before and after food intake. Participants with PTSD, regardless of trauma source, reported higher purging frequency whereas PTSD due to SA was associated with more frequent loss of control eating. For one task, changes in negative affect following food intake differed across the three groups. Negative affect decreased significantly in participants with PTSD without SA whereas nonsignificant increases were observed in those with PTSD with SA. Results of the present study suggest that source of trauma in PTSD may impact likelihood that eating regulates affect and provide insight into ways current treatments may be adapted to better target purging in BN-S comorbid with PTSD.