Incremental validity of weight suppression in predicting clinical impairment in bulimic syndromes

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Two diagnostic schemes were used: the DSM-5 diagnostic scheme and an alternative scheme where atypical anorexia nervosa superseded all diagnoses except anorexia nervosa.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.

Validation of the Portuguese version of the Clinical Impairment Assessment (CIA) in eating disorders' patients

PURPOSE

The purpose of the study was to assess the psychometric properties of the Portuguese version of the Clinical Impairment Assessment (CIA) in eating disorders (ED) patients.

METHOD

The CIA is a 16-item brief self-reported instrument developed to assess psychosocial impairment secondary to EDs. The CIA was administered to a clinical sample of 237 women with EDs and a college sample of 196 women. The clinical sample completed the Eating Disorders Examination Questionnaire, the Beck Depression Inventory and the Outcome-45 Questionnaire. Reliability, confirmatory factor analysis, validity, and clinically significant change were calculated.

RESULTS

Confirmatory factor analysis validated the original 3-factor structure showing an adequate model fit. CIA showed good psychometric properties with high internal consistency, good convergent validity with the EDE-Q, the OQ-45, and the BDI. For divergent validity, participants CIA scores in the clinical sample were significantly higher than in the non-clinical sample. ROC curve analysis provided a cutoff of 15. For known-groups validity participants' scoring above CIA cutoff reported significantly higher CIA scores. In addition, non-underweight participants and participants reporting the presence of dysfunctional ED behaviors had significantly higher CIA scores. Finally, for clinically significant change, a reliable change index of 5 points was obtained to consider a reliable change in the CIA global score.

CONCLUSIONS

Our findings support the validity and clinical utility of the CIA as a good self-report measure to be used in both clinical and research settings.

LEVEL OF EVIDENCE

Level V. Cross-sectional descriptive study.

Weight suppression and its relation to eating disorder and weight outcomes: a narrative review

Weight suppression (WS) refers to the discrepancy between highest adult weight and current weight, and has been examined as a key construct related to both: eating pathology and weight management. However, despite increasing interest in WS, findings regarding the clinical implications of WS are often conflicting. For instance, WS has been associated with both adaptive and maladaptive outcomes across various populations. Moreover, results regarding the predictive utility of WS within clinical samples have been inconsistent. The current paper aims to provide a narrative review of existing investigation related to WS, highlight gaps in the field's understanding of this construct, and outline recommendations for future study.

Weight Suppression in Eating Disorders: a Research and Conceptual Update

PURPOSE OF REVIEW

Weight suppression, the discrepancy between an individual's highest past weight at adult height and his or her current weight, is related to many characteristics of individuals with eating disorders. This paper reviews research findings from the past 5 years, draws several implications regarding the mechanism underlying these effects, and proposes new approaches to measuring weight suppression.

RECENT FINDINGS

Studies were reviewed under the categories of anorexia nervosa, bulimia nervosa, and mixed or miscellaneous samples, with more studies falling into the last category than in the first two. Recent findings have continued to show that weight suppression is related to a wide variety of biological and behavioral features in both diagnosed and sub-clinical samples. Weight suppression promotes weight gain which is anathema to individuals with eating disorders, putting them in a biobehavioral bind that appears to prolong their disorder. Priorities for future research are to understand the mechanisms underlying the effects of weight suppression, evaluate new ways of defining weight suppression, and study its implications for modifying treatment.

Relation of BMI and weight suppression to eating pathology in undergraduates

Weight suppression (WS), the difference in one's highest and current adult weight excluding pregnancy, is associated with eating disorder (ED) symptom onset and maintenance. There is increasing evidence that WS is related to ED symptoms in non-clinical samples, but there are no known studies examining the interaction of WS and current body mass index (BMI) in this group. History of overweight is common in those with EDs, and higher weight status often delays identification and treatment. This study examined the interaction of WS and current BMI on body dissatisfaction and eating pathology in undergraduate men and women. Undergraduates (N = 476) completed online surveys assessing current height and weight, weight history, and eating attitudes and behaviors. In women (n = 333), both BMI and WS were positively associated with body dissatisfaction, restraint, and global ED symptoms. In men (n = 143), there were no significant associations with BMI, but WS was related to greater body dissatisfaction, restraint, global ED symptoms, and loss-of-control eating. Moderation analyses revealed that the effect of current BMI on shape concern (p = .005), weight concern (p = .002), global ED symptoms (p = .01), and purging behaviors (p = .04) in women and restraint (p = .03) in men weakened at the highest levels of WS. Results suggest that WS is salient in a non-clinical sample and underscore the need to evaluate both weight history and the presence of disordered eating in individuals across the BMI spectrum.

Addressing Weight Suppression to Improve Treatment Outcome for Bulimia Nervosa

Cognitive behavioral therapy (CBT) is regarded as the gold-standard treatment for bulimia nervosa (BN), yet despite impressive empirical support for its effectiveness, over 50% of patients fail to achieve abstinence from binge eating and purging by the end of treatment. One factor that may contribute to reduced efficacy rates in CBT is weight suppression (WS; the difference between a person's highest weight ever at their adult height and current weight). A growing body of research indicates that WS in patients with BN may have a clinically significant effect on symptomatology and prognosis. However, the current cognitive behavioral framework for BN does not explicitly acknowledge the role of WS in the onset or maintenance of BN symptoms and does not provide guidance for clinicians on how to address WS during treatment. The relationship between WS, biological pressure to regain lost weight, and the maintenance of BN symptoms suggest that current cognitive behavioral models of BN may be improved by considering the role of WS and exploring needed treatment modifications. Indeed, a reconceptualization of existing models may offer insight into potential strategies that can be used to reduce the susceptibility to treatment dropout, nonresponse, and relapse. It is therefore necessary to consider whether, and how, clinicians' consideration of WS during case conceptualization and treatment planning could serve to improve CBT outcomes. The current review explores ways in which high WS could contribute to poor CBT outcomes, provides preliminary clinical recommendations for incorporating WS into existing cognitive behavioral treatments based on extant data and clinical wisdom, and proposes suggestions for future research needed in this domain.

The impact of weight suppression and weight loss speed on baseline clinical characteristics and response to treatment

OBJECTIVE

Growing evidence suggests an impact of weight suppression (WS) on severity and course of symptoms in patients with eating disorders (ED), but no study explored also the role of the weight loss speed (WLS) together with WS on the same clinical variables, which is the aim of the present work.

METHOD

A mixed cross-sectional and longitudinal cohort study was employed. Four hundred and fourteen patients with anorexia nervosa (AN = 208) or bulimia nervosa (BN = 206) according to DSM-5 criteria were recruited and assessed at referral by means of clinical interviews and self-reported questionnaires. Body mass index and diagnostic status were re-evaluated at the end of treatment.

RESULTS

WS was positively correlated with body dissatisfaction in patients with AN (p = .005), but negatively correlated in BN (p = .022). In contrast, WLS was significantly inversely correlated with age and duration of illness in all ED (p < .001), and positively correlated with drive for thinness in BN (p = .007). After treatment, WS at intake predicted higher BMI increase in both AN and BN (p < .03), while higher WLS was significantly associated with a lower drop-out rate in patients with BN (p = .02), and predicted BMI increase only in restricting AN patients (p = .02). In the whole group, WLS significantly predicted remission status (p = .039).

DISCUSSION

In our study, both WS and WLS were associated with baseline "core" clinical variables and provided complementary abilities to predict weight gain and remission at the end of treatment. If replicated, our data suggest the importance of considering both WS and WLS as useful clinical variables in the baseline assessment of ED.

Exploring gender differences in the link between weight suppression and eating pathology

Weight suppression (WS), the difference in one's highest weight (excluding pregnancy) and current weight at current height, is associated with the onset of eating disorders. Previous research has explored the influence of WS in predominantly clinical, female samples. However, the transition to college is a particularly high-risk time for weight gain and the development of eating pathology and men with eating disorders often have higher premorbid weights. This study investigated the associations of WS and dimensions of eating pathology in an undergraduate sample (N=859) and examined the effect of gender. Results demonstrated that higher levels of WS were associated with more dietary restraint (p=0.004) and more frequent purging behaviors (p<0.001); WS was indirectly related to loss-of-control eating through dietary restraint for both men and women (p<0.001). Additionally, men with higher WS were more likely to engage in extreme weight control behaviors, such as vomiting and laxative abuse (p=0.036). Findings suggest that weight history might be especially important to assess in men at risk for disordered eating. This approach might be particularly beneficial with college students due to their heightened risk of eating and weight disturbances.