Using Continuous Glucose Monitoring to Detect and Intervene on Dietary Restriction in Individuals With Binge Eating: The SenseSupport Withdrawal Design Study

Using Continuous Glucose Monitoring to Passively Classify Naturalistic Binge Eating and Vomiting Among Adults With Binge-Spectrum Eating Disorders: A Preliminary Investigation

OBJECTIVE

Binge eating and self-induced vomiting are common, transdiagnostic eating disorder (ED) symptoms. Efforts to understand these behaviors in research and clinical settings have historically relied on self-report measures, which may be biased and have limited ecological validity. It may be possible to passively detect binge eating and vomiting using data collected by continuous glucose monitors (CGMs; minimally invasive sensors that measure blood glucose levels), as these behaviors yield characteristic glucose responses.

METHOD

This study developed machine learning classification algorithms to classify binge eating and vomiting among 22 adults with binge-spectrum EDs using CGM data. Participants wore Dexcom G6 CGMs and reported eating episodes and disordered eating symptoms using ecological momentary assessment for 2 weeks. Group-level random forest models were generated to distinguish binge eating from typical eating episodes and to classify instances of vomiting.

RESULTS

The binge eating model had accuracy of 0.88 (95% CI: 0.83, 0.92), sensitivity of 0.56, and specificity of 0.90. The vomiting model demonstrated accuracy of 0.79 (95% CI: 0.62, 0.91), sensitivity of 0.88, and specificity of 0.71.

DISCUSSION

Results suggest that CGM may be a promising avenue for passively classifying binge eating and vomiting, with implications for innovative research and clinical applications.

Continuous glucose monitoring as an objective measure of meal consumption in individuals with binge-spectrum eating disorders: A proof-of-concept study

OBJECTIVE

Going extended periods of time without eating increases risk for binge eating and is a primary target of leading interventions for binge-spectrum eating disorders (B-EDs). However, existing treatments for B-EDs yield insufficient improvements in regular eating and subsequently, binge eating. These unsatisfactory clinical outcomes may result from limitations in assessment and promotion of regular eating in therapy. Detecting the absence of eating using passive sensing may improve clinical outcomes by facilitating more accurate monitoring of eating behaviours and powering just-in-time adaptive interventions. We developed an algorithm for detecting meal consumption (and extended periods without eating) using continuous glucose monitor (CGM) data and machine learning.

METHOD

Adults with B-EDs (N = 22) wore CGMs and reported eating episodes on self-monitoring surveys for 2 weeks. Random forest models were run on CGM data to distinguish between eating and non-eating episodes.

RESULTS

The optimal model distinguished eating and non-eating episodes with high accuracy (0.82), sensitivity (0.71), and specificity (0.94).

CONCLUSIONS

These findings suggest that meal consumption and extended periods without eating can be detected from CGM data with high accuracy among individuals with B-EDs, which may improve clinical efforts to target dietary restriction and improve the field's understanding of its antecedents and consequences.

Does hopelessness predict treatment outcomes in adults with binge-spectrum eating disorders?

Using data from 165 adult participants who enrolled in four studies of cognitive-behavioral therapy (CBT) for binge-spectrum eating disorders (EDs), this secondary analysis examined 1) whether pretreatment hopelessness predicted posttreatment eating pathology, loss-of-control (LOC) eating frequency, and purging frequency; 2) whether treatment had an indirect effect on those outcomes through change in hopelessness; and 3) whether treatment had an indirect effect on hopelessness through those ED measures. The Eating Disorder Examination was used to assess overall eating pathology, LOC frequency, and purging frequency. Hopelessness was measured with one item from the Beck Depression Inventory-II. Regression models showed that pretreatment hopelessness predicted posttreatment LOC eating frequency but not overall eating pathology or purging frequency. Single-group tests of indirect effects showed no effect of reduction in hopelessness on reduction in ED symptoms, but there was an effect of reduction in ED symptoms on reduction in hopelessness.

The relationship between non-purging compensatory behaviors, clinical severity, and treatment outcomes in adults with binge-spectrum eating disorders

Non-purging compensatory behaviors (NPCB; e.g. driven exercise, fasting, other extreme behaviors) are a subcategory of compensatory behaviors typically characterized as infrequent and less severe. Limited prior research has studied NPCB despite their increasing prevalence among adults with binge-spectrum eating disorders (B-ED). More research is needed to understand the types of NPCB present among B-ED and the association between NPCB, clinical severity, and treatment outcomes. Secondary analyses were conducted among 155 adults with B-ED in cognitive-behavioral (CBT)-based clinical trials. At baseline and post-treatment, clinical interviews of eating pathology assessed binge eating frequency, purging compensatory behavior frequency, and global eating pathology. The following NPCB were also assessed: driven exercise, 24-h fasting, 8+ waking hours of compensatory fasting, chewing and spitting, and other extreme weight control behaviors. Participants engaging in NPCB reported higher global eating pathology than those not engaging in NPCB. Frequency of chewing and spitting and 24-h fasting significantly decreased over treatment. Engagement in NPCB at baseline did not predict CBT outcomes. The current study highlights the prevalence and clinical severity of NPCB in B-ED but offers promising results regarding the potential for CBT to improve these behaviors. More research is needed on other extreme weight control behaviors reported qualitatively in our sample and on the maintenance of improvements in non-purging behaviors after CBT.

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.