Understanding momentary associations between body dissatisfaction and exercise in binge-spectrum eating disorders

A naturalistic examination of feeling fat: Characteristics, predictors, and the relationship with eating disorder behaviors

OBJECTIVE

Although literature implicates feeling fat in the maintenance of binge-spectrum eating disorders (EDs; e.g., bulimia nervosa, binge-ED), research in this area is small, nascent, and relies on retrospective self-report. The current study sought to understand the temporal pattern of feeling fat and its role as a precipitant and consequence of ED behaviors.

METHODS

Totally 106 treatment-seeking adults with binge-spectrum EDs completed 7-14-day ecological momentary assessments. They rated feeling fat, negative affect states, and reported on ED behaviors six times per day. Multilevel models evaluated whether feeling fat mediates prospective links between negative affect states and ED behaviors, assessed if negative affect states mediate the prospective association of feeling fat on ED behaviors, and examined the bidirectional prospective association between feeling fat and ED behaviors.

RESULTS

Feeling fat was highest in the early morning (6-8:59 a.m.). Individuals with binge-ED-spectrum EDs demonstrated greater variability in feeling fat than those with bulimia nervosa-spectrum EDs who had stable and high levels of feeling fat. Guilt, sadness, anxiety, and the overall NA at Time 2 mediated the prospective associations between at Time 1 feeling fat and Time 3 dietary restraint, actual dietary restriction, and compensatory exercise. There was a bidirectional prospective association between feeling fat and binge eating.

DISCUSSION

Feeling fat serves as a proximal predictor and mediator of the prospective association between guilt and binge eating. Feeling fat and binge eating mutually reinforce each other.

PUBLIC SIGNIFICANCE

Little is understood regarding the experience of feeling fat in natural environments among individuals with binge-spectrum eating disorders. We found that the risk for having the experience of feeling fat is high in the morning and evening. Feeling fat triggers guilt, anxiety, and sadness which in turn, increases engagement in dietary restraint/restriction and compensatory exercise. Feeling fat also triggers binge eating, and binge eating leads to feelings of fatness.

Daily instability in body dissatisfaction in individuals with and without eating disorders

Body dissatisfaction (BD) includes negative thoughts and feelings about one's body shape. Although typically assessed as a trait, BD has been found to fluctuate within a day. The present study examined whether daily instability in BD differs according to trait BD, eating disorder (ED) diagnosis, and engagement in maladaptive exercise. Participants with EDs (n = 166) and controls (n = 44) completed a self-report measure of trait BD and reported BD and engagement in maladaptive exercise five times daily for 14 days as part of an ecological momentary assessment protocol. BD instability was calculated as adjusted mean squared successive difference. On average across assessments, participants with EDs reported a 16% change in their BD ratings between consecutive assessments, which was significantly higher than the 12% change in controls. Trait BD was significantly inversely associated with BD instability in individuals with EDs, but not in controls. BD instability did not differ across ED diagnoses or between days with versus without maladaptive exercise. Findings suggest that BD is a dynamic state that varies within a day, especially in participants with EDs. Further research is needed to clarify whether this heightened instability in BD is a clinically relevant factor underlying ED symptoms.

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.

Divergent trajectories of positive affect following maladaptive and non-maladaptive exercise among individuals with binge-spectrum eating disorders

OBJECTIVE

Individuals with eating disorders (EDs) often engage in maladaptive exercise (e.g., feeling driven, or to "compensate" for eating) which maintains eating pathology. Maladaptive exercise has been theorized to help individuals with EDs regulate emotions by enhancing positive affect (PA) and reducing negative affect (NA) associated with binge episodes and poor body image. However, no research has considered the presence of non-maladaptive exercise or evaluated this theory in binge-spectrum EDs.

METHODS

This study evaluated affective trajectories pre- and post-exercise and examined exercise type (maladaptive or non-maladaptive) as a moderator. We recruited adults with binge-spectrum EDs (N = 107; n = 84 endorsed exercise) to complete a 7- to 14-day ecological momentary assessment protocol assessing NA (anxiety, guilt, and sadness), PA (excitement and cheerfulness), and exercise.

RESULTS

There was a significant quadratic trajectory of PA pre-exercise, suggesting that the upward trajectory of PA leveled out as it moved closer to an exercise episode. Exercise type significantly moderated the cubic trajectory of PA post-exercise, such that the upward trajectory of PA accelerated in the hours following non-maladaptive exercise episodes while the downward trajectory of PA accelerated in the hours following maladaptive exercise episodes. No trajectories of NA demonstrated significant effects.

CONCLUSIONS

Pre-exercise trajectories of PA may reflect positive expectancies around exercise. Post-exercise trajectories of PA suggest that non-maladaptive exercise promotes increased PA. Future research should evaluate when, and for whom, exercise serves to regulate affect and examine other momentary risk factors of exercise in EDs.

PUBLIC SIGNIFICANCE

Individuals with EDs often engage in maladaptive exercise (e.g., feeling driven, or to "compensate" for eating). Maladaptive exercise has been theorized to help individuals with EDs regulate emotions. This study evaluated affective trajectories pre- and post-exercise and examined whether exercise type (maladaptive or non-maladaptive) changed these trajectories. Pre-exercise trajectories of PA may reflect positive expectancies around exercise. Post-exercise trajectories of PA suggest that non-maladaptive exercise promotes increased PA.

Reward mediates the association between engagement in noneating activities and state body dissatisfaction: An ecological momentary assessment study

OBJECTIVE

Momentary worsening (i.e., greater than one's average levels) of state body dissatisfaction (BD) has been implicated as a proximal risk factor for eating disorder (ED) behaviors in binge-spectrum EDs. Yet, research exploring the prospective association between noneating activities in daily life (e.g., chores, self-care/coping) and momentary state BD remains limited. Understanding the momentary link between engagement in noneating activities and state BD, and pathways through which engagement in said activities influences momentary state BD is critical to informing treatments. The current ecological momentary assessment (EMA) study examined whether (1) engagement in noneating activities at Time 1 prospectively predicted momentary state BD at Time 2 and (2) reward drawn from noneating activities at Time 1 mediates the prospective association between engagement in noneating activities at Time 1 and momentary state BD at Time 2.

METHOD

Sixty-six adults with transdiagnostic binge eating completed an EMA protocol over 7-14 days. Participants received six EMA signals per day (total EMA observations = 4038). Multilevel modeling was used to examine the research questions.

RESULTS

Engagement in an indoor hobby, outdoor recreation, socializing, and self-care/coping strategies prospectively predicted momentary state BD improvements, while using TV/social media and cooking prospectively predicted momentary state BD worsening. Reward drawn from engagement in these noneating activities mediated the associations.

DISCUSSION

If replicated, these findings suggest that increasing the frequency of certain noneating activities and enhancing their rewarding aspects to improve state BD and decrease ED behavior risk during treatment may be worthy of further exploration.

PUBLIC SIGNIFICANCE

Momentary worsening of state body dissatisfaction (BD) is a risk factor for eating disorder behaviors in individuals with binge eating. This study found that engaging in certain noneating activities (e.g., socializing) prospectively predicted momentary improvements in state BD, while other noneating activities (e.g., cooking) predicted momentary worsening of state BD. Reward drawn from activities mediated these relations. To improve state BD, treatments should target the frequency of, and reward obtained from these noneating activities.