2.1 Interoception

A foundational aspect of self-awareness is interoception, which refers to the body’s ability to regulate its internal state through reflexes and adaptive responses. This process entails the regulation and stabilization of the internal physiological state of the body through homeostatic reflexes and adaptive, anticipatory (allostatic) responses. These responses are coordinated among organic systems and drive adaptive behaviors (Craig, Reference Craig2002). From an evolutionary perspective, this foundational level is associated with the physiological conditions of the body, making it integral to the concept of self-representation (Damasio, Reference Damasio1999, Reference Damasio2010).

Being aware of stimuli and variations within the body allows us to perceive sensations such as thirst, nausea, the need to use the bathroom, hunger, and satiety. The transmission of information from the body to the brain occurs precisely to establish a dynamic and comprehensive representation of the physical self, which in turn coordinates behavioral responses to address these physiological needs (Craig, Reference Craig2002). Although a significant portion of this process functions automatically through reflexes, the emergence of awareness initially stems from bodily sensations and emotional states. (Mograbi et al., Reference Mograbi, Huntley and Critchley2021; Treasure et al., Reference Treasure, Duarte and Schmidt2020). Hence, it becomes evident that the concept of body awareness encompasses interoception as a representation of the body’s internal state. This initial stage of awareness refers to the process by which the nervous system senses, interprets, and integrates signals originating from within the body, providing a moment-to-moment mapping of the body’s internal landscape across conscious and unconscious levels (Khalsa et al., Reference Khalsa, Adolphs, Cameron, Critchley, Davenport, Feinstein, Feusner, Garfinkel, Lane, Mehling, Meuret, Nemeroff, Oppenheimer, Petzschner, Pollatos, Rhudy, Schramm, Simmons and Stein2018).

Three interoceptive skills have been suggested: accuracy, sensitivity, and awareness (Critchley & Garfinkel, Reference Critchley and Garfinkel2017; Joshi et al., Reference Joshi, Graziani and Del-Monte2021). Interoceptive accuracy can be defined as the objective ability to detect internal states. Interoceptive sensitivity represents dispositional tendencies to be internally self-focused. Finally, interoceptive awareness indicates the level of self-knowledge, that is, the degree to which the subject perceives themselves capable of accurately judging their interoceptive sensations. Linked to these interoceptive abilities is an understanding of time. Time perception and estimation arise from the accumulation of bodily information and have been connected not only to interoceptive processes but also to subjective orientation, autobiographical memories, and emotion regulation (Richter & Ibáñez, Reference Richter and Ibáñez2021; Meneguzzo et al., Reference Meneguzzo, Mancini, Ormitti, Bonello and Todisco2022). Moreover, the impaired ability to estimate time in patients with ED seems to be related to compulsive self-monitoring (Meneguzzo et al., Reference Meneguzzo, Mancini, Ormitti, Bonello and Todisco2022). The overestimation of time in individuals with AN and the underestimation of time in those with BN can provide insights into the high levels of distress experienced by these patients (Holman & Grisham, Reference Holman and Grisham2020).

Following from that, hunger and satiety, which, as internal states of the body, also encompass accuracy, sensitivity, and awareness. Therefore, it is speculated how accurate, sensitive, and aware an individual with an eating disorder is. It is well known that dysfunctional processing of internal bodily cues related to hunger and satiety is a significant factor in disordered eating behaviors such as binge eating, purging, and cognitive restraint (Poovey et al., Reference Poovey, Ahlich, Attaway and Rancourt2022). This interoceptive sensitivity presents itself as a crucial risk factor to address in screenings and interventions for disordered eating.

Recent research has identified a disturbance in the interoceptive system as a central mechanism underlying AN and BN. This disturbance affects various aspects of physiological condition interpretation, including hunger and satiety perception, risk prediction errors, emotional awareness, time accuracy, and body dysmorphia (Jacquemot & Park, Reference Jacquemot and Park2020; Meneguzzo et al., Reference Meneguzzo, Mancini, Ormitti, Bonello and Todisco2022).

Furthermore, studies utilizing magnetic resonance imaging to measure postprandial gastric volumes have revealed that one in three AN patients experience feelings of fullness and lack of hunger even when their stomachs are empty (Bluemel et al., Reference Bluemel, Menne, Milos, Goetze, Fried, Schwizer, Fox and Steingoetter2017). This suggests that disturbances in satiety perception in AN may arise from the interpretation and perception of visceral signals rather than differences in visceral sensitivity. Additionally, other modalities of interoception besides gastric distension may be implicated, as hunger ratings in AN patients have paradoxically decreased in response to insulin-induced hypoglycemia (Nakai & Koh, Reference Nakai and Koh2001). These misinterpretations of hunger and satiety signals could contribute to food avoidance and disrupted eating habits in AN (Jacquemot & Park, Reference Jacquemot and Park2020).

Indeed, intuitive eating, characterized by the regulation of food intake based on visceral cues of hunger and satiety, correlates positively with interoceptive accuracy while showing a negative association with disordered eating patterns (DeVille et al., Reference DeVille, Erchull and Mailloux2021). This ability to detect internal bodily cues, termed “interoceptive awareness,” along with the subsequent response to these cues, known as “interoceptive responsiveness,” plays pivotal roles in this process (Oswald et al., Reference Oswald, Chapman and Wilson2017). From this perspective, enhancing bodily cognition represents a crucial pathway toward reducing body misperception (Meneguzzo et al., Reference Meneguzzo, Dal Brun, Collantoni, Meregalli, Todisco, Favaro and Tenconi2023).

2.2 Proprioception and body ownership

Body awareness is guided by the representation of the physical extent of the body and the relative position of body parts in space, known as proprioception (Serino et al., Reference Serino, Alsmith, Costantini, Mandrigin, Tajadura-Jimenez and Lopez2013). Proprioception enhances the sense of owning a body and understanding its spatial location. Through this dynamic representation of proprioceptive information, one can become aware of their physical presence within a spatial context. Unlike the largely implicit nature of interoceptive information, proprioceptive information offers greater conscious access (Mograbi et al., Reference Mograbi, Huntley and Critchley2021, Reference Mograbi, Hall, Arantes and Huntley2024).

It is understood that body awareness results from the interaction between body image and schema, leading to a subjective sensation of one’s body (Thurm, Reference Thurm2012). The body schema allows individuals to recognize and perceive the various components of their own body, forming the perception of its dimensions regardless of body acceptance, self-esteem, or body type (Thurm, Reference Thurm2012). Perceived body image pertains specifically to an individual’s subjective perception or mental representation of their own physical appearance. In contrast, schema refers to broader cognitive frameworks that organize and interpret information across various domains, including beliefs, attitudes, perceptions, and expectations about oneself, others, and the environment (Young, Reference Young1999; Boone et al., Reference Boone, Braet, Vandereycken and Claes2013). It relies on multimodal sensory inputs, including exteroception, proprioception, vestibular, somatosensory, and visual systems (Riva, Reference Riva2014). Regarding proprioception specifically, it is important to assess the degree of body distortion, perception of specific body segments, the sensory aspects of freely projected body perception, and the perception of body boundaries – with or without visual or cognitive interference, as well as any external reference (Thurm et al., Reference Thurm, Miranda, Salzano, Cangelli Filho, Cordás and Gama2011; Riva, Reference Riva2014).

Based on clinical reports and a narrative review of the literature, it has been observed that patients with ED experience a distortion between their perceived body image and schema and their actual reality (Thurm, Reference Thurm2012; Miller, Reference Miller1991; Longo & Haggard, Reference Longo and Haggard2012; Pellegrini et al., Reference Pellegrini, Finzi, Veglia and Di Fini2021; Riva, Reference Riva2014). Consequently, individuals with ED exhibit a significantly stronger response to the rubber hand illusion, both in terms of perceptual (proprioceptive bias) and subjective (self-report) measures, compared to healthy controls (Eshkevari et al., Reference Eshkevari, Rieger, Longo, Haggard and Treasure2014). This suggests that individuals with a history of ED may have heightened sensitivity to visual information about their bodies while exhibiting reduced processing of somatosensory information (Eshkevari et al., Reference Eshkevari, Rieger, Longo, Haggard and Treasure2014).

Therefore, clinical interventions aim to reduce proprioceptive deviation, distortion, and dissatisfaction, while facilitating self-reintegration (Miller, Reference Miller1991; Longo & Haggard, Reference Longo and Haggard2012). The interventions proposed to stimulate personal space align with the primary somatosensory representation involved in structuring body perception, which occurs through exteroceptive and proprioceptive stimuli (Longo & Haggard, Reference Longo and Haggard2012; Riva, Reference Riva2014). These stimuli contribute to the formation of the body’s perceived boundaries. Since individuals with ED experience imprecision in perceiving their body dimensions, it is crucial to stimulate this representation to provide more accurate information about body dimensions to other cortical areas.

It is widely understood that our sense of self is closely related to both our physical bodies and our personal identity. Consequently, the formation and organization of our body image are integral aspects of our overall identity. From this perspective, the maintenance of an ED directly affects the subject’s identity (Pellegrini et al., Reference Pellegrini, Finzi, Veglia and Di Fini2021; Longo & Haggard, Reference Longo and Haggard2012). In line with self-objectification theory, which posits that individuals come to view themselves as objects to be evaluated based on appearance, the maintenance of an ED can exacerbate this tendency (Fredrickson & Roberts, Reference Fredrickson and Roberts1997). Given that our understanding of our bodies plays a central role in assigning meaning to our experiences, addressing factors such as body interactions, sensorimotor patterns, and proprioceptive patterns is crucial in ED treatment (Pellegrini et al., Reference Pellegrini, Finzi, Veglia and Di Fini2021; Longo & Haggard, Reference Longo and Haggard2012).

2.3 Agency

Agency, or the sense of initiating our actions, plays a crucial role in self-awareness, often distinguishing clinical and non-clinical individuals (i.e., those not seeking medical or clinical treatment or evaluation). Action and agency are closely related, with the sense of agency encompassing self-efficacy through the awareness of deliberate control over one’s behavior. It involves recognizing intentional control over one’s actions (Haggard, Reference Haggard2017). When exploring this concept, the literature proposes a distinction between the feeling of agency and the judgment of agency. While the feeling of agency captures implicit, non-conceptual sensations of being an agent of action, explicit higher-level agency judgment is influenced by prior knowledge, expectations, and beliefs (Zapparoli et al., Reference Zapparoli, Paulesu, Mariano, Ravani and Sacheli2022). The latter aligns with metacognition and holds significance in psychotherapeutic treatment.

A sense of agency enhances our understanding of important processes in psychotherapy (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019). In clinical psychology, agency has been defined as the ability to experience thoughts, emotions, and behaviors as belonging to the self and being under the influence and control of the self (Kögler, Reference Kögler2010; Williams & Levitt, Reference Williams and Levitt2007). The sense of agency can be measured in experimental settings by asking participants to explicitly judge whether their action caused an outcome event, or by using implicit measures, such as the compression of perceived time between action and outcome (Haggard, 2017). Thus, one can evaluate the concept of agency based on the degree to which a person believes they can impact their target experiences and behaviors (Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023). For instance, a patient’s sense of agency regarding symptoms of bulimia nervosa can be assessed concurrently with treatment (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019).

Empirical findings can be assessed through different paradigms of implicit sense of agency in ED patients. Sensory attenuation, for example, consists of the fact that self-produced tactile stimulation is perceived as less intense than the same stimulus produced externally (Blakemore et al., Reference Blakemore, Frith and Wolpert1999). This paradigm explains the difference between people’s intensity perception of tactile stimuli delivered by themselves (self-generated condition) and the stimuli delivered by other individuals (other-generated condition). This difference in perception gives rise to the so-called sensory attenuation phenomenon, in which the intensity of self-generated stimuli is perceived as significantly attenuated compared to the same stimuli generated by someone else. This phenomenon occurs because people automatically anticipate the sensory consequences of self-generated actions, explaining why people are unable to tickle themselves (Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023). Particularly, the first studies in this area show that in ED patients, there is an opposite pattern of behavior, with self-generated stimuli perceived as more intense than other-generated stimuli. This result indicates an alteration of the implicit component of the feeling of control in ED patients and alterations in the sense of agency (Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023).

Another paradigm is control feedback, which refers to a motivational factor: sensitivity to our degree of control over the environment (Eitam et al., Reference Eitam, Kennedy and Tory Higgins2013). When actions have even trivial and constant perceptual effects, motivation to perform is enhanced. Eitam et al. (Reference Eitam, Kennedy and Tory Higgins2013) show that increased motivation is not explained solely by the availability of more information about task performance; rather, motivation increases only in conditions where control over the effects can be firmly established by the mind. Regarding EDs, it is known that the feeling of being out of control is present in AN and BN patients, especially in the latter (Adler et al. Reference Adler, Brown, Shott, Swindle and Frank2022; Brownstone et al., Reference Brownstone, Bardone-Cone, Fitzsimmons-Craft, Printz, Le Grange, Mitchell, Crow, Peterson, Crosby, Klein, Wonderlich and Joiner2013). On the other hand, AN patients do not experience a self-perceived loss of control over eating (Adler et al. Reference Adler, Brown, Shott, Swindle and Frank2022; Brownstone et al., Reference Brownstone, Bardone-Cone, Fitzsimmons-Craft, Printz, Le Grange, Mitchell, Crow, Peterson, Crosby, Klein, Wonderlich and Joiner2013). This may suggest that individuals with AN are aware that they can maintain control over eating, not least because they have restricted food intake resulting in significantly low body weight (Adler et al. Reference Adler, Brown, Shott, Swindle and Frank2022). Thus, AN behaviors may help maintain a sense of control and support the motivational sensitivity of the symptoms. Individuals with EDs appear to control their eating, weight, and shape as a way to address their perceived lack of control over interpersonal and overall life stressors, and these behaviors could be attempts at establishing control and managing internal uncertainty surrounding life events.

In relation to the need for control, we can also access agency by applying degrees of uncertainty (Perrykkad et al., Reference Perrykkad, Lawson, Jamadar and Hohwy2021). It is known that uncertainty over actions negatively influences the sense of agency. Among all our sensations, we need to distinguish between those caused by ourselves and those caused by external factors (Perrykkad et al., Reference Perrykkad, Lawson, Jamadar and Hohwy2021). Such paradigms, which modulate uncertainty, might provide more informative insights into the sense of agency in AN, as AN patients experience higher anxiety and a greater need for control in uncertain situations (Sternheim et al., Reference Sternheim, Konstantellou, Startup and Schmidt2011; Frank et al., Reference Frank, Roblek, Shott, Jappe, Rollin, Hagman and Pryor2012). The ability to infer agency is particularly challenging under conditions of uncertainty, and although the literature has not yet investigated this issue specifically in EDs, it could be a promising approach to exploring agency in this group.

Although the rubber hand illusion may offer greater insights into the proprioception domain, we can also evaluate the feeling of ownership of the fake hand. When AN patients experience a stronger sense of ownership over the rubber hand than healthy individuals (Keizer et al., Reference Keizer, Smeets, Postma, van Elburg and Dijkerman2014), we can begin to understand not only the intensity of the feeling of agency but also its accuracy. In this case, AN patients seem to have a false yet robust sense of agency (Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023).

The concept of agency can be particularly complex within the realm of ED. For instance, in AN, the need to maintain a sense of control is central (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019; Engel et al., Reference Engel, Ainley, Tsakiris, Chris Dijkerman and Keizer2022). Patients with this diagnosis often perceive their symptoms as a solution to their problems (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019; Bruch, Reference Bruch1973). Therefore, anorexic patients show a false yet powerful sense of agency (Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023). Conversely, individuals within the bulimic spectrum may experience a loss of control during compulsive episodes. In such cases, the sense of agency can be considered weak when the patient feels helpless or overwhelmed by ED-related emotions, thoughts, and behavioral symptoms (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019). This dysregulation of the sense of agency occurs because ED symptoms often serve to shield individuals from feelings of inferiority and negative emotions (Kristmannsdottir et al., Reference Kristmannsdottir, Keski-Rahkonen and Kuusinen2019). Gaining a deeper understanding of a patient’s agency can facilitate the adaptation of treatment approaches and methods that are best suited to their capacity for change. Consequently, enhancing the sense of agency may be an important objective in the treatment of ED (Engel et al., Reference Engel, Ainley, Tsakiris, Chris Dijkerman and Keizer2022; Colle et al., Reference Colle, Hilviu, Boggio, Toso, Longo, Abbate-Daga, Garbarini and Fossataro2023).

2.4 Metacognition

Metacognition can be defined as the knowledge and cognitive processing involved in evaluating, monitoring, and regulating one’s own cognition (Flavell, Reference Flavell1979). It is a capacity observed, at different complexity levels, in a variety of species (Lage et al., Reference Lage, Wolmarans and Mograbi2022), being compromised in a number of neuropsychiatric disorders, such as obsessive-compulsive disorder and psychosis (Mograbi et al., Reference Mograbi, Hall, Arantes and Huntley2024). Recent systematic review and meta-analysis articles have highlighted the association between ED and dysfunctional metacognition, specifically focusing on metacognitive beliefs and maladaptive metacognitive patterns such as rumination (Palmieri et al., Reference Palmieri, Mansueto, Ruggiero, Caselli, Sassaroli and Spada2021; Smith et al., Reference Smith, Mason and Lavender2018, Sun et al., Reference Sun, Zhu and So2017). In the context of ED, it is understood that dysfunctional metacognitions play a pivotal role in maintaining maladaptive coping strategies, thus contributing to the development and persistence of symptoms (Palmieri et al., Reference Palmieri, Mansueto, Ruggiero, Caselli, Sassaroli and Spada2021; Spada et al., Reference Spada, Mohiyeddini and Wells2008).

Rumination is considered a central feature in ED (Smith et al., Reference Smith, Mason and Lavender2018; Palmieri et al., Reference Palmieri, Mansueto, Ruggiero, Caselli, Sassaroli and Spada2021). In this metacognitive process, individuals repetitively focus on seeking out meanings, causes, and consequences of their negative emotions. This pattern of repetitive thoughts is configured as an amplifying cycle: rumination accentuates the negative mood state and, consequently, generates mood-congruent cognitions that increase repetitive thinking. This, in turn, reinforces and exacerbates the negative mood state (Nolen-Hoeksema et al., Reference Nolen-Hoeksema, Wisco and Lyubomirsky2008). Importantly, patients with ED exhibit higher levels of rumination compared to healthy individuals. Furthermore, rumination is also associated with high levels of symptoms when only diagnosed patients are compared with each other (Smith et al., Reference Smith, Mason and Lavender2018). Difficulties in the capacity for cognitive flexibility have also been observed in this group of patients (Roberts et al., Reference Roberts, Tchanturia, Stahl, Southgate and Treasure2007; Tchanturia et al., Reference Tchanturia, Anderluh, Morris, Rabe-Hesketh, Collier, Sanchez and Treasure2004), emphasizing the relevance of repetitive thinking in the characterization of this condition. In the case of ED, rumination primarily manifests in relation to topics such as food, weight, shape, or physical appearance (Davenport et al., Reference Davenport, Rushford, Soon and McDermott2015). It has also been suggested that symptoms such as excessive focus on food and body weight and shape are actually forms of rumination specific to these disorders (Cowdrey & Park, Reference Cowdrey and Park2011).

The occurrence and persistence of ruminative thoughts are associated with the metacognitive beliefs presented by an individual, as observed in both clinical and non-clinical samples (Palmieri et al., Reference Palmieri, Mansueto, Scaini, Fiore, Sassaroli, Ruggiero, Borlimi and Carducci2018). The main metacognitive beliefs observed in patients with ED include negative attributions to worries, such as the belief that worries are uncontrollable, lower levels of cognitive confidence (self-efficacy in decision-making and problem-solving), and higher levels of cognitive self-awareness, characterized by a tendency to focus on the self and monitor one’s thoughts (Smith et al., Reference Smith, Mason and Lavender2018; Palmieri et al., Reference Palmieri, Mansueto, Ruggiero, Caselli, Sassaroli and Spada2021). The belief regarding the need to control thoughts is also considered particularly relevant in the context of ED (Olstad et al., Reference Olstad, Solem, Hjemdal and Hagen2015). For instance, patients often express thoughts such as “I should always be in control of my thoughts” or “Not being able to control my thoughts indicates weakness.” These beliefs can be triggered by rumination frames, where the idea that “worries are unmanageable” arises when one finds themselves caught in a cycle of negative thoughts. Additionally, these beliefs can reinforce the repetitive thought pattern; for example, by believing that thoughts must be controlled, individuals reinforce the importance of constantly observing and analyzing them.

It is important to highlight the potential cyclical effect between maladaptive metacognitive beliefs and rumination. It is evident that rumination contributes to the consolidation of a negative mood state in this patient group, while also hindering engagement in more constructive forms of cognitive processing that could help regulate dysfunctional behaviors. Thus, taking a metacognitive perspective is essential when addressing ED.

2.5 Emotional regulation

There is an evident relationship between metacognitive processes and the ability to regulate emotions (Mograbi et al., Reference Mograbi, Huntley and Critchley2021). The latter can be defined as the ability to modulate one’s affective experiences through cognitive, behavioral, intra-, and interpersonal strategies (Gross, Reference Gross2002). Capabilities such as self-awareness of one’s emotions and the construction and execution of strategies aimed at goals and demands, necessary for adequate emotional regulation (Gratz & Roemer, Reference Gratz and Roemer2004), involve metacognitive properties by definition. In fact, a direct association is observed between metacognitive beliefs, thought rumination, and emotional dysregulation, even in samples from the general population (Mansueto et al., Reference Mansueto, Marino, Palmieri, Offredi, Sarracino, Sassaroli, Ruggiero, Spada and Caselli2022). This relationship is hypothesized to have reciprocal causality, meaning that beliefs, metacognitive processes, and psychopathological mood symptoms mutually affect each other (Capobianco et al., Reference Capobianco, Heal, Bright and Wells2019).

Thus, it is not surprising that deficits in emotion regulation capacities are a central characteristic of ED (Ruscitti et al., Reference Ruscitti, Rufino, Goodwin and Wagner2016). A recent meta-analysis identified a strong association between maladaptive emotion regulation strategies and the symptomatology of such disorders (Leppanen et al., Reference Leppanen, Brown, McLinden, Williams and Tchanturia2022). Interestingly, reduced use of acceptance, along with the adoption of strategies such as emotion suppression and avoidance, is also associated with dietary restriction habits in non-clinical populations (Mikhail & Kring, Reference Mikhail and Kring2019). However, compared to psychiatric patients with other diagnoses, patients with ED face greater levels of difficulty with emotion regulation, including the ability to accept affective responses, achieve goals when affected by intense emotional states, and identify and understand their own emotions (Ruscitti et al., Reference Ruscitti, Rufino, Goodwin and Wagner2016).

In binge-eating disorder, emotional dysregulation, specifically difficulty controlling impulses, is associated with the severity of the episodes (Aloi et al., Reference Aloi, Rania, Carbone, Caroleo, Calabrò, Zaffino, Nicolò, Carcione, Coco, Cosentino and Segura-Garcia2021). It is understood that this relationship is mediated by the ability to self-monitor, so difficulties with recognizing one’s own emotions play a key role in the development and maintenance of this disorder (Prefit et al., Reference Prefit, Cândea and Szentagotai-Tătar2019; Westwood et al., Reference Westwood, Kerr-Gaffney, Stahl and Tchanturia2017). An episode of binge eating can also be understood as a maladaptive emotion regulation strategy. In this sense, the ingestion of a large amount of food would be an attempt to alleviate negative feelings, but it would be dysfunctional as it causes new negative emotions at the end of the episodes (Leehr et al., Reference Leehr, Krohmer, Schag, Dresler, Zipfel and Giel2015; Hilbert & Tuschen-Caffier, Reference Hilbert and Tuschen-Caffier2007). On the other hand, patients with anorexia nervosa or bulimia nervosa report feelings of pleasure or relief from implementing strategies such as food restriction or purging (Ruscitti et al., Reference Ruscitti, Rufino, Goodwin and Wagner2016). These behaviors can also be understood as attempts at emotional regulation. For example, food restriction to the point of causing starvation can reduce both the internal affective experience and the expression of emotions, helping the individual to avoid unwanted states (Leppanen et al., Reference Leppanen, Brown, McLinden, Williams and Tchanturia2022). However, these strategies still constitute maladaptive approaches due to their resulting physical and emotional consequences. Despite possible distinctions in the specific skills and strategies within each condition, a meta-analysis found no differences in the existence and intensity of deficits in emotion regulation between the disorders. This finding reinforces the transdiagnostic nature of emotional dysregulation in eating disorders (Prefit et al., Reference Prefit, Cândea and Szentagotai-Tătar2019).

In the realm of eating disorders (EDs), ambulatory assessment methods, particularly Ecological Momentary Assessment (EMA), have emerged as valuable tools for investigating the dynamic nature of ED symptoms in naturalistic settings (Maugeri & Barchitta, Reference Maugeri and Barchitta2019). These methods allow researchers to examine the type, frequency, and temporal sequencing of symptoms as they occur in real-time (Smith & Juarascio, Reference Smith and Juarascio2019). Additionally, there’s a growing interest in utilizing Ecological Momentary Interventions to target ED symptoms more effectively. These methodologies involve real-time data collection methods, based on repeated evaluations of emotions, behaviors, or experiences on a portable electronic device (e.g., a smartphone) throughout the day (at random or at specific moments) in natural environments (Walenda et al., Reference Walenda, Bogusz, Kopera, Jakubczyk, Wojnar and Kucharska2021).

Negative emotions and deficits in their regulation are significant contributors to EDs, with increased negative emotions often preceding binge-eating episodes (Puttevils et al., Reference Puttevils, Vanderhasselt, Horczak and Vervaet2021). Individuals with BED and BN experience heightened negative affect, particularly anxiety, and depression, leading up to binge-eating episodes, with fluctuations in mood and emotional states throughout the day often exacerbating those episodes (Walenda et al., Reference Walenda, Bogusz, Kopera, Jakubczyk, Wojnar and Kucharska2021). EMA methodology research represents a way to focus on emotional changes related to the binge cycle, identifying its reinforcing factors, for instance.

Consistent with these observations, individuals with AN have demonstrated patterns of emotional dysregulation characterized by heightened negative affect, particularly anxiety and distress, preceding and following eating episodes or meal times (Puttevils et al., Reference Puttevils, Vanderhasselt, Horczak and Vervaet2021). Individuals with AN often engage in maladaptive emotion regulation strategies such as avoidance or cognitive control, contributing to the maintenance of disordered eating behaviors (Wayda-Zalewska et al., Reference Wayda-Zalewska, Grzegorzewski, Kot, Skimina, Santangelo and Kucharska2022).

EMA studies can provide a wealth of data, including dietary, behavioral, physical, socio-psychological, and contextual information, facilitating the examination of concurrent exposures and events (Maugeri & Barchitta, Reference Maugeri and Barchitta2019). These methods hold promise in various fields of nutritional epidemiology, from identifying determinants of dietary habits in healthy individuals to managing patients with eating or metabolic disorders. However, efforts to improve the validity, reliability, and technological innovations of EMA are encouraged for advancing public health research and interventions.

2.6 Autobiographical memory

Autobiographical memory is defined as the memory systems that encode, consolidate, and retrieve personal events and facts (Fossati, Reference Fossati2013). Because it is strongly related to self-representation, autobiographical remembering reflects an advanced state of consciousness that mediates awareness of the self as continuous across time (Levine, Reference Levine2004). It also contributes to a sense of self, allowing autonoetic consciousness, time and travel, the ability to re-experience details, and therefore the development of self-knowledge (Lenzoni, Morris & Mograbi, Reference Lenzoni, Morris and Mograbi2020; Morris & Mograbi, Reference Morris and Mograbi2013). In this context, a particularity of ED is the patient’s experience of identity (Riva, Reference Riva2014).

Unlike many other conditions, EDs are also, to some extent, experienced positively by these patients (Vanderlinden, Reference Vanderlinden2008; Serpell et al., Reference Serpell, Treasure, Teasdale and Sullivan1999). This is because some of their maladaptive eating behaviors have social functionality, such as providing a sense of belonging, adequacy, control, and alignment with their belief system (Riva, Reference Riva2014). Considering this direct relationship between the disorder and identity, it is relevant to discuss the association of the former with autobiographical memory, which plays a crucial role in the construction of identity and a sense of self (Wilson & Ross, Reference Wilson and Ross2003). In fact, different studies point to the existence of alterations in autobiographical memory processes in patients with ED. For example, patients with anorexia nervosa have been observed to have difficulties in accessing emotional memories (Ková et al., Reference Ková, Szabo and Paszthy2011), integrating positive and negative emotional experiences (Nandrino et al., Reference Nandrino, Doba, Lesne, Christophe and Pezard2006), and developing narrative discourse (Gandolphe et al., Reference Gandolphe, Nandrino, Hendrickx, Willem, Cottencin, Gérardin, Guardia, Buttitta, Zanini and Dodin2021). Additionally, these patients may exhibit a lack of specificity in autobiographical memories related to sensitive topics, such as food and the body (Terhoeven et al., Reference Terhoeven, Nikendei, Faschingbauer, Huber, Young, Bendszus, Herzog, Friederich and Simon2023; Huber et al., Reference Huber, Salatsch, Ingenerf, Schmid, Maatouk, Weisbrod, Herzog, Friederich and Nikendei2015). They also report intense emotional activation and negative valence when recalling such experiences (Zhu et al., Reference Zhu, Hu, Wang, Chen, Guo, Li and Enck2012). It is speculated that this overgeneralization of memories may serve as an avoidant regulatory mechanism (Oldershaw et al., Reference Oldershaw, Lavender, Sallis, Stahl and Schmidt2015; Treasure & Schmidt, Reference Treasure and Schmidt2013). It is also known that overgeneral autobiographic memory disturbance is related to affective disorders and may represent a risk factor for depression, even due to possible comorbidity (Fang & Dong, Reference Fang and Dong2022).