Binge-spectrum eating disorders (EDs), including bulimia nervosa (BN) and binge eating disorder (BED), are serious psychological disorders characterized by recurrent episodes of binge eating (ie, eating an excessive amount of food while experiencing a sense of loss-of-control over one’s eating) and may be accompanied by behaviors intended to compensate for these episodes (eg, vomiting or restricting food intake). Binge-spectrum EDs typically start during adolescence [1] and have a 7% to 8% prevalence among adolescents [2,3]. Critically, gold-standard treatments for binge-spectrum EDs fail to produce remission in 60% to 75% of adolescents [4-6], and only about 50% of individuals stay remitted 5 years following treatment [7]. These low remission rates indicate that available treatments do not sufficiently address all mechanisms maintaining the ED. Indeed, following treatment, many continue to experience ED symptoms, despite no longer meeting diagnostic criteria for an ED [6,8]. In particular, body image disturbances remain elevated following treatment [9,10], and studies have identified elevated body image disturbances as a risk factor for relapse [11]. These findings are consistent with the transdiagnostic model of cognitive behavioral therapy (CBT) for EDs, which points to the overvaluation of weight, shape, eating, and their control as the core psychopathology underlying these disorders [12], thereby suggesting that until overvaluation is addressed, individuals may continue to experience ED symptoms. Given the low remission rates among adolescents with binge-spectrum EDs, it is critical to understand how the overvaluation of shape, weight, and eating manifests among adolescents and how it relates to ED symptomology.

One behavioral manifestation of overvaluation with weight, shape, eating, and their control is body checking [13]. Body checking refers to a broad range of behaviors used to assess one’s weight or shape (eg, self-weighing, checking how clothes fit, pinching or feeling various body parts) [14]. Based on studies among adults with EDs, these behaviors have a 90% prevalence [13,15]; are often engaged in compulsively; are brief, typically lasting less than two minutes [13]; and can occur multiple times in a given day. For example, in a transdiagnostic, qualitative study of adults with anorexia nervosa and BN, 92% of adults endorsed body checking and 33% of adults reported body checking 16 or more times in a given day [13]. Likewise, in 2 ecological momentary assessment (EMA; ie, an ecologically valid data sampling approach that prompts participants multiple times over the study period) studies among female college students with high weight and shape concern, participants body checked an average of 16 to 28 times a day [16,17]. However, no study has yet attempted to estimate how frequently body checking occurs among adolescents, let alone those with binge-spectrum EDs.

Critically, body checking behaviors are typically aimed toward disliked body parts [14], and selectively attending to disliked body parts and their perceived changes may contribute to increased ED cognitions, particularly body dissatisfaction and body image disturbances, and behaviors [18]. In transdiagnostic adult ED samples, body checking is associated with increased dietary restriction, meal skipping, use of fluids to curb appetite [19,20], increased negative affect [21,22], and shape and weight overconcern [15]; among those with binge-spectrum EDs, body checking is additionally indirectly tied to binge eating through increased body shame and appearance anxiety [23]. Further, 1 longitudinal study found that in a community sample of adolescents, higher body checking at 1 time point was associated with the development of ED symptoms 4 months later [24], underscoring the need for early and targeted interventions for body checking behaviors in this age group. Indeed, adolescents report high rates of body image dissatisfaction [25], a prominent driver of ED pathology among adolescents [26-28]. In recent years (ie, 2017‐2022), the prevalence of EDs has dramatically increased among adolescent female participants [29]. Despite this, few studies have examined the associations between body checking behaviors and ED symptomology among adolescents with binge-spectrum EDs.

Given the strong theoretical links between body checking behaviors and ED symptomology, body checking may, itself, be a worthwhile target for intervention. In fact, 2 EMA studies among female college students found small decreases in body checking behaviors as well as body dissatisfaction and internalization of the thin ideal. These reductions can be understood as effects of self-monitoring. In cognitive-behavioral models of psychopathology, the self-monitoring of behaviors and psychological states is key for reducing engagement in undesirable behaviors and cognitions [30], including body dissatisfaction [31], ruminative thinking [32], suicidal ideation [33], depressive symptoms [34], sedentary behaviors [35], and substance use [36]. Self-monitoring theoretically increases the awareness of the frequency, antecedents, and consequences of problematic thoughts and behaviors [30], allowing individuals to make changes either independently or with the support of a clinician. It is possible that during EMA, participants experience reductions in body checking frequency because reporting these behaviors on EMA surveys similarly increases the awareness for the frequency, antecedents, and consequences of these behaviors. Thus, in addition to examining associations between body-checking behaviors and ED symptomology in the real world, it is also worthwhile to investigate how these behaviors may decrease in response to self-monitoring. Notably, if body checking behaviors show reductions during EMA in adolescents with binge-spectrum EDs, and if these reductions are associated with improvements in other ED symptoms, then digital self-monitoring may be a powerful tool to formalize body checking as an intervention target in evidence-based treatments such as enhanced cognitive behavior therapy (CBT-E) or as a stand-alone treatment. Given the large ED treatment gap (eg, less than 20% of individuals with EDs receive care [37]), the scalability of digital self-monitoring could prove valuable among those engaging in body checking [16,17] prior to the receipt of more intensive treatment or as a prevention tool, particularly among adolescents.

Despite the relevance of body checking as a maintenance factor for ED pathology, relatively little is known about the nature of body checking and its prospective associations with ED cognitions and behaviors among adolescents with binge-spectrum EDs. Thus, this study aims to fill 3 specific gaps. The first aim of this study is to characterize the types and frequency of body checking behaviors among adolescent girls (ages 14‐19 years) with binge-spectrum EDs during a 3-week EMA protocol. Although body checking behaviors are present across the ED spectrum, they have most frequently been studied within restrictive EDs, despite the evidence of their presence within binge-spectrum EDs [13] and associations with binge eating [23]. Similarly, while body checking is prevalent among boys [24], consistent with other studies [16,17], we elected to restrict this study to girls because measures in this study would fail to capture the different behaviors used to body check and their associations with ED behaviors in boys [38,39]; further, resource constraints (ie, limited budget and personnel) precluded the recruitment of boys. We expect that participants will report a broad range of body checking behaviors and that they will engage in body checking behaviors several times a day on average. The second aim of the study is to test prospective associations between body checking and other ED symptoms. Consistent with the CBT model for EDs, we expect that body checking will be concurrently and prospectively associated with cognitive (ie, body dissatisfaction, fear of weight gain) and behavioral (ie, dietary restriction or restraint, compensatory behaviors) ED symptoms. The third aim is to assess whether the self-monitoring of body checking produces decreases in body checking over time. We hypothesize that body checking will decrease over the study period and that participants will report lower frequencies of body checking on the last 3 days of the protocol compared to the first 3 days [16,17].

Prior to study enrollment, informed consent will be obtained from the parent or from the adolescents if they are 18 years or older. Adolescents under 18 years will also need to provide assent to participate. All study procedures have received approval from the Drexel University Institutional Review Board, under protocol number 2401010341. All participants will be compensated up to US $275 for their participation (see the “Ecological Momentary Assessment” section for more details). Data will be stored securely on Drexel’s encrypted servers, and analytic datasets will be stripped of identifiers.

We will enroll 70 adolescent girls with clinically significant binge eating (ie, engaging in at least 1 binge eating episode per week over the past 12 weeks). Both subjective and objective binge episodes will be counted given literature demonstrating that the feeling of loss of control, rather than the size of the binge episode, is more closely linked to ED severity [40,41]. Thus, to be included in the study, participants will need to be between 14 and 19 years old; be able to speak, read, and write English; have a smartphone they would be willing to complete daily surveys on for the course of the study; and were assigned female at birth. Participants will be excluded if they are currently receiving treatment for binge eating and/or weight loss or if they will be starting treatment during the course of the study, if they have begun a course of or changed the dosage of any medication known to affect appetite or body composition in the past 3 months, if they are currently pregnant or have plans to become pregnant, or if they have a developmental disability (eg, autism spectrum disorder) or are currently experiencing severe psychopathology that would limit their ability to engage in the study or would otherwise pose a risk to their safety (eg, severe depression, substance dependence, active psychotic episode, imminent suicide risk). The final 2 exclusion criteria will be assessed in consultation with a licensed clinical psychologist. Although such criteria may exclude certain individuals who represent the broader clinical population, these criteria are in place to ensure participant safety during this observational study.

To date, there is limited literature on the role of body checking in maintaining binge-spectrum EDs among adolescents [12,14,23,53]. Thus, this study will provide valuable insights into the types, frequencies, and effects of body checking behaviors on ED symptoms among adolescents with binge-spectrum EDs. The findings from this study will clarify whether body checking behaviors are prospectively associated with engagement in other ED symptoms and may provide direction for research on mediators and moderators of this relationship, which is critical for better understanding maintaining mechanisms of EDs in adolescents. Furthermore, this study will evaluate whether body checking shows reductions when subject to self-monitoring during EMA. If our hypotheses are supported and body checking behaviors decrease along with other ED symptoms, this study could inform the importance of formally targeting body checking during treatments, such as CBT-E, and could inform clinicians’ decisions around which symptoms to prioritize. Further, the findings from this study may provide a stepping stone for the development of scalable, stand-alone interventions to reduce body checking behaviors. Although such stand-alone interventions will not replace gold-standard approaches such as CBT-E, they represent a low-cost, accessible option for individuals with EDs that could be used as an adjunct to available treatments or a brief intervention while patients await the receipt of more comprehensive treatment. Digital self-monitoring could also have high utility as a tool for ED prevention, given literature which supports that higher engagement in body checking in adolescents is longitudinally linked to the development of ED symptoms [24]. Future research should aim to pilot such digital interventions to establish preliminary acceptability and feasibility.

The strengths of this study include the use of a transdiagnostic sample of adolescents with binge-spectrum EDs, which will improve the generalizability of the results. Furthermore, the inclusion of a broad range of body checking behaviors, as opposed to assessing body checking with 1 or 2 items as past literature has done [20], will provide critical insights into the frequency and timing of these behaviors among adolescents.

The limitations of this study include the lack of follow-up assessments, which make it difficult to assess reactive effects to self-monitoring, whether body checking continues to decrease, plateaus, or eventually increases back to baseline. Likewise, given that adherence to self-monitoring may have a dose-response relationship with reactive reductions in body checking, it is possible that the incentives used to increase compliance (ie, financial compensation and personalized reminder texts with memes and GIFs) may confound aim 3. Given that incentives are needed to promote compliance, otherwise data missingness would preclude the detection of hypothesized relationships, future studies might consider varying sampling procedures (eg, fewer surveys per day) to more carefully test for a dose-response relationship between self-monitoring via EMA and body checking. Future work should examine these behaviors over longer periods and include follow-up assessments to better understand how effectively self-monitoring intervenes on body checking and how decreases in body checking may correlate with reductions in other indices of ED pathology. Of note, given the EMA design of this study, it is possible that reductions in other ED behaviors may be driven by self-monitoring or may arise from reductions in the overvaluation of shape and weight, as manifest by body checking. This study is further limited by its exclusion of boys. Given that boys use a different set of methods to body check [39], future work should use questionnaires, such as the Male Body Checking Questionnaire, to assess body checking in boys [38]. Likewise, given heterogeneity in body image ideals across cultures [54], it is possible measures used in this study will not appropriately capture body checking behaviors, and caution is warranted when examining racial or ethnic differences in body checking. Finally, although we used EMA items reported in other studies [16,17,52,55], including those with adolescents, some of these items have yet to undergo proper validation efforts, particularly for administration among adolescents.

In conclusion, this study will elucidate the nature and frequency of body checking, body checking’s prospective relations to ED symptoms, and the potential reactivity of body checking to digital self-monitoring (via EMA) among adolescent girls with binge-spectrum EDs. The data afforded by this study will be critical for understanding the presentations of body checking in adolescents’ daily lives and how it may maintain binge-spectrum EDs. This study will also inform optimal strategies for intervening on body checking and improving long-term ED treatment outcomes in adolescents with EDs.