affective-touch. also, the body schema is overextended. some research suggested that this is related to a general enlarged mental representation of body size. a 2017 study published in a companion journal to nature highlighted how perceptual disturbance is present in those recovered from anorexia nervosa even without affective-cognitive body concerns. finally, interoception, the sense of the current state of the body, is problematic in those with eating disorders. onset the age of onset for body image disturbance is often early adolescence, the age in which one's comparison to their peers becomes more significant and leads to a greater sensitivity towards criticism of, or teasing about, one's physical appearance. furthermore, puberty leads to rapid changes in body size and shape that need to be integrated into one's body image. for this reason, adolescence is considered a critical age, with a greater vulnerability to internalizing ideals of thinness, which may ultimately lead to the development of body dissatisfaction, body image disturbance, or eating disorders. in a 2019 review, sattler and colleagues analyzed eight on-topic studies. the authors found that most adolescents with anorexia nervosa and bulimia nervosa already had body-checking behaviors, negative body-related emotions and feelings, low body satisfaction, and an altered estimate of their body size compared to healthy controls. unfortunately, exactly how one passes from initial dissatisfaction with one's body to actual perceptual disorder is still unknown despite its clinical importance. the etiopathogenesis is still unknown and the subject of hypotheses in the clinical and neuroscientific fields. relationship to other concepts body dissatisfaction body dissatisfaction and body image disturbance are closely related. personal, interpersonal, cultural, social, and ethnic variables largely influence bodily dissatisfaction, influencing the emergence of painful feelings towards one's body. in addition, social pressure is considered a risk factor for body dissatisfaction. for example, the frequent presence on media of thin female bodies determines, especially in young girls, a daily comparison between their bodies and models and actresses favoring bodily dissatisfaction; comparing an "ideal" and "real" body feed an intense dissatisfaction with one's body and increases the feeling of shame, disgust, and anxiety towards the one's body and appearance. dissatisfaction with one's body involves only three of the four components of the body image. those with bodily dissatisfaction can have negative thoughts about one's body (e.g., "i'm ugly" or "i'm too short"). in addition, they may have behaviors related to bodily dissatisfaction (e.g., going on a diet or resorting to cosmetic surgery) . they may also have negative feelings of dissatisfaction with their body and be ashamed of showing it in public. however, all these aspects are not enough to define it as a body image disturbance. in fact, there is no perceptual alteration of one's body. thus, "body image disturbance" cannot be used interchangeably with "body dissatisfaction", but they are closely related. body dysmorphic disorder body image disturbance in anorexia and body dysmorphic disorder (bdd) are similar psychiatric conditions that both involve an altered perception of the body or parts of it but are not the same disorder. body image disturbance is a symptom of anorexia nervosa (an) and is present as criterion c in the dsm-5, and alters the perception of weight and shapes of the whole body. patients with anorexia nervosa believe that they are overweight, perceive their body as being "fat" and misperceive their body's shape. body dysmorphic disorder, meanwhile, is an obsessive-compulsive disorder characterized by disproportionate concern for minimal or absent individual bodily flaws, which cause personal distress and social impairment—patients with body dysmorphic disorder are concerned about physical details, mainly the face, skin, and nose. thus, both anorexia nervosa and body dysmorphic disorder manifest significant disturbances in body image but are different and highly comorbid. for example, grant et al reported that 39% of an patients in their sample had a comorbid diagnosis of body dysmorphic disorder, with concerns unrelated to weight. cerea et al reported that 26% of their an sample had a probable bdd diagnosis with non-weight-related body concerns. while a 2019 review by phillipou et al in psychiatry research suggested that the two disorders could be taken together as "body image disturbances", plural, more in-depth studies are needed to confirm this new classification hypothesis. similarities previous studies found that both bdd and eating disorder groups were similar in body dissatisfaction, body checking, body concerns, and levels of perfectionism. furthermore, both bdd and an patients report higher intensities of negative emotions, lower intensities of positive emotions, lower self-esteem, and anxiety symptoms. moreover, research find severe concerns about one's appearance, leading to a continuous confrontation with others' bodies in both diseases. in addition, body image disturbances and body dysmorphic disorder generally onset during adolescence. finally, alterations in visual processes seems to be present in both disorders, with greater attention to detail, but with greater difficulty in perceiving stimuli holistically. indeed, neurophysiology and neuroimaging research suggests similarities between bdd and an patients in terms of abnormalities in visuospatial processing. differences despite many similarities, the two disorders also have significant differences. the first is gender distribution. body image disturbance is much more present in females, unlike bdd, which has a much less unbalanced incidence. furthermore, those with dysmorphophobia tend to have more significant inhibitions and avoidance of social activities than those with anorexia nervosa. differences are self-evident when considering the focus of physical concerns and misperception in an and bdd. whereas bdd patients report concerns and misperception in specific body areas (mainly face, skin, and hair), in patients with an the altered perception could involve the arms, shoulders, thighs, abdomen, hips, and breasts, and concerns are about overall body shape and weight. thus, leading to an alteration of the entire explicit (body image) and implicit (body schema) mental representation of the body. furthermore, in anorexia nervosa, not only is visual perception of one's body altered, but both tactile and interoceptive perception are as well. diagnosis body image disturbance is not yet clearly defined by official disease classifications. however, it appears in the dsm-5 under criterion c for anorexia nervosa and is vaguely described as "a disturbance in the way weight and body shapes are experienced". as a result, diagnosis is usually based on reported signs and symptoms; there are still no biological markers for body image disturbance. numerous psychometric instruments to measure the cognitive, affective, and behavioral components of one's body image are used in clinical and research settings, helping in assessing the body image's attitudinal components. recently, research developed other instruments to measure the perceptive component. attitudinal assessment tools the eating disorder inventory 3 (edi-3) represents an improvement of the earlier versions of the edi, a self-report questionnaire widely used both in research and clinical settings. it consists of 91 questions, and items are rated on a six-point likert scale (always, usually, sometimes, rarely, never), with higher scores representing more severe symptoms. precisely, the bd subscale of edi-3 measures bodily dissatisfaction. the body uneasiness test (but) is a self-administered questionnaire. it explores several areas in clinical and non-clinical populations: weight phobia, body image-related avoidance behavior, compulsive self-monitoring, detachment and estrangement feelings toward one's own body. besides, explore specific worries about particular body parts, shapes, or functions. higher scores indicate significant body uneasiness. the body image disturbance questionnaire investigates different areas related to body image disturbance. for example, it evaluates the parts of the body an individual finds most problematic, the psychological effects of their worries about their body, and effects on their social life and eating behavior. the body shape questionnaire is a 34-item self-assessment questionnaire designed to measure the degree of dissatisfaction with the weight and shape of one's body. it includes questions about the fear of weight gain and about whether one has the urge or desire to lose weight. the body checking questionnaire measures the frequency of body control behaviors, such as measuring specific body areas, using mirrors to check or avoid body shape, wearing loose-fitting, covering clothing, or checking for bony prominence with one's hands. higher scores indicate a higher frequency of body checking behaviors. perceptual assessment tools bid-ca (test for body image distortion in children and adolescents): patients with a 180 cm rope simulate the circumference of the different parts of the body, including the hips, thighs, shoulder width and other parts of the body considered phobic. this estimate is compared to the actual patient size. the procedure is validated for children and adolescents but can also be used in adults. visual size estimation task (vse): patients are placed standing in front of a wall at a distance of about one meter. they place two stickers on the wall that reflect the perceived dimensions of different body parts, such as the width of the shoulders, hips, or waistline. these values are then taken and compared with those measured directly on the patient. tactile estimation task (tet): a standard gauge is used for measurement. during the measurement, patients estimate the distance between the two points of the gauge while it is placed on different parts of the body. several measurements are made and the gauge is oriented in different directions (for example, at the height of the hips, it is placed both horizontally and vertically) 3d morphing: numerous 3d modeling computer programs allow directly modifying a human body model by increasing or decreasing its size. patients modify the 3d avatar so that it represents their body image as closely as possible. the model values are then compared with the actual measurements of the patients. multi-sensory perception the perception of one's body is a multi-sensory process that integrates information deriving from different sensory cortices, including the visual, proprioceptive, tactile, interoceptive, and auditory-vestibular areas. all of these areas are involved in the perception of one's body. an important component is the premotor cortex (pmc) and the intraparietal sulcus. these two areas are active during illusory hand perception tasks in both hemispheres. the somatosensory areas are also involved, in particular the primary somatosensory cortex (s1). an important area is the extrastriate body area located rostrocaudally in the occipital lobe and is specific to human bodies perception. two other areas of considerable importance in the perception of the body are the insula and the anterior cingulate cortex. the insular cortex is fundamental in the direct perception and integration of bodily signals from different cortical areas and, despite being an area historically delegated to the sole function of perceiving the state of internal organs as proposed by sherrington in 1911, research advances demonstrate the central role of the insula in several domains, including the recognition that one's body belongs to us. namely the "body ownership". brain imaging fmri studies examining brain responses in anorexia nervosa patients to paradigms that include body image tasks have found altered activation across different brain areas, including the prefrontal cortex, precuneus, parietal cortex, insula, amygdala, ventral striatum, extrastriate body area, and fusiform gyrus. however, as janet treasure commented, "the research is fragmented, and the mechanism of how these areas map onto the functional networks described above needs further study ... the mechanism by which the extremes of body distortion are driven and circuitry is not known yet." prevention the body project is an eating disorder prevention program within a dissonant-cognitive framework. the program provides a forum for high school girls and college-age women to confront unrealistic-looking ideals and develop a healthy body image and self-esteem. it has been repeatedly shown to effectively reduce body dissatisfaction, negative mood, unhealthy diet, and disordered eating. treatments of cognition, affect, and behavior historically, research and clinicians have mainly focused on body image disturbance's cognitive, affective, and behavioral components. consequently, treatments generally target symptoms such as body checking, dysfunctional beliefs, feelings, and emotions relating to the body. one of the best-known psychotherapies in the field is cbt-e. cbt-e is a cognitive-behavioral therapy that has been enhanced with particular strategies to address the psychopathology of eating disorders. these include reducing negative thoughts and worries about body weight and shape, reducing clinical perfectionism, and body-checking behavior. in 2020 a review has shown that cbt-e effectively reduces core symptoms in eating disorders, including concerns about the body. despite this, the results of cbt-e are no better than other forms of treatment. a therapy of choice for eating disorders in adults has not yet been identified. additionally, two other noteworthy body image treatments are thomas f. cash's "body image workbook" and bodywise. the former is