Binge eating involves rapidly and uncontrollably eating a large amount of food in a short time period. Research suggests that binge eating is common among people seeking bariatricFootnote 1 (weight-management) services with prevalence rates upwards of 50 %. Binge eating is associated with poorer weight loss and weight regain after bariatric services or alternative attempts at weight loss [1, 2]. Given the high rates of binge eating among people seeking bariatric services and its negative impact on weight-loss outcomes [1–3], targeting binge eating in patients seeking bariatric services may be useful to enable optimal treatment response. However, programs aimed at targeting binge eating are not routinely offered in bariatric programs. This manuscript describes the implementation and evaluation of a targeted intervention for binge eating among a group of patients accessing bariatric services.

The intervention used in the present study was adapted from Linehan’s [4] manualized dialectical behavior therapy (DBT) and Safer, Telch, and Chen’s [5] manualized dialectical behavior therapy for binge eating (DBT-BE). The theory underlying this treatment is based upon the affect regulation model that suggests binge eating is used in an attempt to manage painful or unpleasant emotional states [6, 7]. Available evidence suggests that DBT-BE is effective in reducing binge eating among community-dwelling, adults with eating disorders [8]. However, to date, no research has tested whether DBT-BE is effective in reducing binge eating among patients seeking bariatric services. The present study addresses this gap by testing the impact that a 10-week DBT-BE skills group has on binge eating and associated psychosocial functioning among patients seeking bariatric services. We hypothesized binge eating and associated psychosocial functioning would improve following participation in the DBT-BE skills group.

Method

Participants and procedure

This study was reviewed and approved by a hospital research ethics board. All patients seeking services with the bariatric care center complete a series of questionnaires, including the questionnaire for eating and weight patterns-revised (QEWP-R), during a general intake meeting. The QEWP-R obtains binge eating frequency and other criteria for the diagnosis of binge eating disorder. The therapists (the first and second author) reviewed patients’ responses to the QEWP-R and contacted those who (1) met the diagnostic and statistical manual of mental disorders (DSM-5) criteria for binge eating disorder, (2) lived within commuting distance to the center, and (3) were waiting for bariatric services. The therapists informed the patients about the upcoming DBT-BE skills group. If patients were interested in receiving more information about the group they were booked for an initial appointment with one of the therapists. During this initial appointment, patients had an opportunity to ask questions and provide informed consent to participate in the DBT-BE skills group. If they chose to join, participants completed a series of baseline questionnaires. Overall, 20 patients were contacted and informed about the group and 11 chose to participate. Of the patients who chose to participate, two were pursuing bariatric surgery and nine were pursuing medical weight management (i.e., 26-week program that includes 12-weeks of meal replacement, gradual transition to food, educational group meetings, and ongoing medical monitoring). To be eligible for bariatric surgery, patients need to be 18 or older and have a body mass index (BMI) >40 kg/m2 or >35 kg/m2 with significant obesity-related medical comorbidities (e.g., hypertension, type 2 diabetes mellitus). To be eligible for medical weight management, patients need to be 18 or older and have a BMI >35 kg/m2 or a BMI between 30 and 35 kg/m2 with at least two medical comorbidities. All participants completed the DBT-BE group prior to undergoing bariatric surgery or beginning the medical weight management program.

Intervention

The intervention was led by the two therapists (the first and second authors) and involved 10 weekly, 2-hour group therapy sessions. Sessions focused on skill development in four areas: mindfulness, emotion regulation, distress tolerance, and interpersonal effectiveness. Mindfulness skills focus on developing moment-to-moment awareness of one’s experiences (e.g., eating) in a non-judgmental way. Emotion regulation skills involve developing an understanding of emotions and vulnerabilities to negative emotions, increasing positive emotions, and changing emotions through opposite-to-emotion action. Distress tolerance skills teach adaptive means of enduring stressors and painful experiences without turning to maladaptive methods of coping (e.g., binge eating). Interpersonal effectiveness skills focus on identifying goals in interpersonal situations and assertively communicating one’s needs. The four skill areas address factors that are relevant to the occurrence and maintenance of binge eating including tendencies to eat mindlessly and turning to food in an effort to cope with unpleasant emotions, crises, and problems in relationships. Following each group session, participants were assigned homework (i.e., practice strategies discussed in group). Participants also completed a diary card each week that focused on tracking their behaviors, emotions, and use of the DBT skills.

Measures

The measures were administered at baseline and post-treatment. All measures have good reliability and validity. Severity of binge eating was assessed with the 16-item Binge Eating Scale. For each item, participants are asked to choose one of four statements (scored 0–3) that best reflect their experience. Higher scores are indicative of more severe binge eating. Evidence suggests this scale has strong psychometric properties.

The Emotional Eating Scale is a 25-item scale that assesses the extent to which specific emotional states (e.g., anger, sadness) contribute to eating urges. Participants rate their desire to eat in response to each emotion (e.g., angry, sad, excited) along a 5-point scale from 1 (no desire to eat) to 5 (an overwhelming urge to eat). Higher scores correspond to greater emotion-driven eating urges. The scale is comprised of three subscales: anger/frustration, anxiety, and depression.

The Negative Mood Regulation Scale is a 30-item scale that measures expectancies regarding one’s ability to alter negative moods. Along a 5-point scale from 1 (strongly disagree) to 5 (strongly agree), participants rate the extent to which they believe that using various strategies can improve their negative mood states. Higher scores reflect stronger beliefs that one can alleviate their negative mood states through adaptive means.

Rosenberg Self-Esteem Scale consists of 10 items that assess global self-worth. Participants rate their response along a 4-point scale from 0 (strongly disagree) to 3 (strongly agree), with lower scores indicating lower self-esteem.

The Patient Health Questionnaire-9 is a 9-item scale that assesses the severity of depressive symptoms. On a 4-point scale from 0 (not at all) to 3 (nearly every day), participants indicate the frequency with which they experienced each symptom over the previous 2-week period.

The General Anxiety Disorder Scale-7 measures generalized anxiety symptoms. Participants rate the frequency that they were bothered by each symptom over the previous 2-week period on a 4-point scale from 0 (not at all) to 3 (nearly every day).

Analyses

Paired samples t tests examined changes in outcome variables from baseline to post-treatment. We used Cohen’s d for calculating the effect size for the difference between two correlated measurements. Cohen defined effect sizes as small (d = .2), medium (d = .5), and large (d = .8). Given the small sample size in this pilot study, nonparametric effects were also measured using Wilcoxon signed ranks tests.

Results

Sample characteristics

Participants averaged 44.56 years of age (SD = 16.31) and the majority self-identified as Caucasian (81.8 %) and female (90.9 %). Based on self-report weight and height, participants had an average body mass index of 50.92 at baseline (SD = 8.84; range = 38.27–61.79) and 46.78 post-treatment (SD = 9.13; range = 36.49–64.01).

Retention

The majority of participants who began the group also completed the group (i.e., 91 %). However, one participant was absent from group on the last day so did not complete the post-treatment measures.

Treatment outcomes

Means, standard deviations, and effect sizes for measures at baseline and post-treatment are presented in Table 1. On average participants showed a significant reduction in binge eating severity from baseline to post-treatment, t(8) = 2.63, p < .05. Nonparametric tests were also statistically significant (Z = −2.07, p < .05).

Table 1 Means, standard deviations, Cronbach’s alphas, and effect sizes
Full size table

Across all other variables (i.e., emotional eating, negative mood regulation, self-esteem, generalized anxiety, depressive symptoms), parametric tests and nonparametric tests yielded no statistically significant differences (p > .05) from baseline to post-treatment despite some sizable effect sizes (see Table 1). Nonparametric tests also failed to reach statistical significance (p > .05).

Discussion

The present study tested the impact that a 10-week DBT-BE skills group has on binge eating and associated psychosocial functioning among patients seeking bariatric services. Hypotheses were partially supported with binge eating significantly decreasing from baseline to post-treatment. Results of this small pilot study are promising and suggest that a DBT-BE skills group would be useful in addressing binge eating for patients who are pursuing bariatric (weight-management) services. The lack of significant change in associated psychosocial functioning may suggest that changes in these variables requires additional time and integration of the skills and/or treatment focused specifically on these difficulties. Low dropout rates also suggest that DBT-BE is acceptable to patients. In fact, dropout rates in this study were much lower than rates reported in other studies targeting binge eating with DBT [8]. However, participants involved in the DBT-BE group were on the waitlist for bariatric services and this may have had an impact on their motivation and may have contributed to a lower than expected dropout rate.

Despite promising results, this study has some limitations including a reliance on self-report data, a small sample size, and a potentially biased selection process (e.g., patients expressing interest in the group may be more motivated than other patients). In addition, the sample was mainly Caucasian women, thus generalizability of the results to other patient groups is unknown. We also did not include a control group in this pilot study. Therefore, a logical next step is to conduct additional research utilizing a randomized controlled design with a larger sample to study the effects of DBT-BE on binge eating and associated psychosocial functioning prior to beginning bariatric services. Moreover, follow-up assessments (e.g., 6-month post-treatment or after completing bariatric services), are needed to determine whether improvements in binge eating are sustained and whether changes in binge eating can improve weight-loss outcomes.