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.

Momentary associations between fear of weight gain and dietary restriction among individuals with binge-spectrum eating disorders.

OBJECTIVE: Fear of weight gain (FOWG) is increasingly implicated in the maintenance of binge-spectrum eating disorders (EDs; e.g., bulimia nervosa [BN], binge-eating disorder [BED]) through the pathway of increased dietary restriction. However, particularly in binge-spectrum EDs, research is nascent and based on retrospective self-report. To improve treatment outcomes, it is critical to better understand the momentary relations between FOWG and dietary restriction. METHOD: Sixty-seven adults with binge spectrum EDs completed a 7-14-day ecological momentary assessment protocol that included items regarding FOWG, ED behaviors, and types of dietary restriction (e.g., attempted restraint vs. actual restriction) several times per day. Multilevel models were used to evaluate reciprocal associations between FOWG and dietary restriction, and to evaluate the indirect of effects of dietary restriction on the relation between FOWG and binge eating. RESULTS: While main effects were not statistically significant, ED presentation significantly moderated the association between increases in FOWG at time1 and both attempted and actual avoidance of enjoyable foods at time2 such that those with BN-spectrum EDs were more likely to avoid enjoyable foods following increased FOWG compared to those with BED-spectrum EDs. Engagement in restriction at time1 was not associated with decreased FOWG at time2. DISCUSSION: Prospective associations between FOWG and restriction suggest that individuals with BN may be more likely to restrict their eating following increased FOWG. These findings suggest FOWG may be an important target for future treatments.

Changes in affect from non-eating activity engagement as predictors of loss of control eating: an ecological momentary assessment study.

PURPOSE: Loss of control eating (LOCE) is supported as a maladaptive regulation strategy for high negative affect (NA) and low positive affect (PA). Yet, little is known about the day-to-day activities outside of eating that may precipitate such changes in affect and impact risk for LOCE. The current ecological momentary assessment study sought to examine whether (1) low NA and high PA at a given survey would prospectively predict lower likelihood of a LOCE episode at the next survey, and (2) having recently engaged in various non-eating activities would be associated with changes in average NA and PA levels at the same survey. METHODS: Data collected from 66 participants with LOCE over 7-14 days were analyzed using generalized estimating equations. RESULTS: High NA but not low PA at a given survey prospectively predicted lower likelihood of a LOCE episode at the next survey. Having recently engaged in outdoor recreation and socializing was associated with lower than one's usual NA and higher than one's usual PA at the same survey, social media was associated with higher than one's usual NA and lower than one's usual PA, self-care was associated with higher than one's usual PA, and napping was associated with lower than one's usual PA. CONCLUSION: Individuals may benefit from increasing the frequency of daily non-eating activities that reduce NA, since it appears to be a more salient predictor of LOCE than PA. Further research is needed to elucidate this LOCE maintenance model, particularly in regard to the role of PA. LEVEL OF EVIDENCE: Level IV, multiple time series without intervention.

The project REBOOT protocol: Evaluating a personalized inhibitory control training as an adjunct to cognitive behavioral therapy for bulimia nervosa and binge-eating disorder.

Outcomes from cognitive behavioral therapy (CBT) for bulimia nervosa (BN) and binge-eating disorder (BED) are suboptimal. One potential explanation is that CBT fails to adequately target inhibitory control (i.e., the ability to withhold an automatic response), which is a key maintenance factor for binge eating. Computerized inhibitory control training (ICT) is a promising method for improving inhibitory control but is relatively untested in BN/BED. The present study will evaluate a computer-based ICT as an adjunct to CBT for BN/BED. Participants with BN (n = 30) or BED (n = 30) will be randomized to 12 weeks of either CBT + ICT or CBT + a sham training. Trainings will be completed daily for 4 weeks and weekly for 8 weeks. Primary aims include the following: (a) confirm target engagement (evaluate whether ICT improves inhibitory control), (b) test target validation (evaluate whether improvements in inhibitory control are associated with improvements in binge eating), and (c) evaluate the incremental efficacy of ICT on binge eating. Secondary aims include the following: (a) evaluate ICT feasibility and acceptability and (b) assess the moderating effects of approach tendencies on highly palatable food, dietary restraint, and diagnosis. Data will be used to shape a fully powered clinical trial designed to assess efficacy and dose-response effects of ICT for BN/BED.

Does virtual reality enhance the effects of inhibitory control training for loss-of-control eating? A pilot factorial experiment.

Inhibitory control, one's ability to inhibit automatic responses to desirable stimuli, may be inadequately targeted in interventions for loss-of-control eating (LOC). Promising evidence has identified inhibitory control trainings (ICTs) as an avenue to target inhibitory control directly; however, effects of ICTs on real-world behavior are limited. Compared to typical computerized trainings, virtual reality (VR) presents several potential advantages that may address key shortcomings of traditional ICTs, i.e. poor approximation to everyday life. The present study utilized a 2 × 2 factorial design of treatment type (ICT vs sham) by treatment modality (VR vs standard computer), which allows for increased statistical power by collapsing across conditions. Our primary aim was to examine the feasibility and acceptability of six weeks of daily training among groups. A secondary aim was to preliminarily assess main and interactive effects of treatment type and modality on target engagement and efficacy (i.e., training compliance, change in LOC episodes, inhibitory control, and implicit liking of foods). Participants (N = 35) with ≥1×/weekly LOC were assigned to one of four conditions and completed ICTs daily for six weeks. The trainings were feasible and acceptable, evinced by high retention and compliance across time and condition. Although completing daily trainings across treatment types and modalities was associated with large decreases in LOC, there were no meaningful effects of either treatment type or modality, nor a significant interaction effect, on LOC or mechanistic variables. Future research should aim to increase the efficacy of ICT (both standard and VR-based) and test in fully-powered clinical trials.

Characterizing reasons for exercise in binge-spectrum eating disorders.

Although 40-60% of individuals with eating disorders (EDs) report engaging in maladaptive exercise, self-reported reasons for engaging in exercise vary. Further, no studies have examined momentary reasons for exercise and whether reasons for exercising could be both adaptive and maladaptive for any episode. Examining reasons for exercise can inform interventions which more effectively target maladaptive exercise. The current study recruited adults with binge-spectrum EDs (N = 58, 89.2% Female) and assessed self-reported reasons for exercise using ecological momentary assessment over 7-14 days. Exercise episodes were categorized as maladaptive if the participant endorsed exercising to compensate for eating or feeling driven to exercise. On average, participants reported exercising 8 times (SD = 8) over the 7-14 days. On average, 73% of exercise episodes were maladaptive. Participants most frequently stated exercising to control shape or weight (67.2% of episodes), feeling driven (62.9%), and exercising as part of a routine (52.9%). Participants least endorsed exercising so that they could eat more later (9.8%). Participants reported a mean of 3.6 reasons for exercising at each episode (SD = 1.85, mode = 1.0). As hypothesized, individuals with EDs were exercising for several reasons at each exercise episode. Further, the extent to which each exercise episode is maladaptive varied between participants and even within a single participant's exercise episodes. These findings underscore the importance of research evaluating when, and for whom, exercise becomes maladaptive, as well as research examining other characteristic features of maladaptive and adaptive exercise in EDs.