with a pulse over 100 bpm suggesting infection or dehydration [29]. Also, basic screening is necessary. A full blood cell count has to be done, biochemical assays such as transaminase to evaluate liver function, creatinine and urea for determining renal function. Electrolytes abnormalities are common and need to be measured to exclude hyponatremia after an excessive water intake, hypokalemia in the context of excessive purging, or hypocalcaemia, hypomagnesaemia that can indicate the improper use of laxatives. Thyroid function should be checked together with plasma ferritin, folate, and B12 vitamin [30].

Body temperature frequently drops under 36°C in anorexic patients, who voluntary induce hypothermia in order to start shivering, consume energy and lose some more weight. Fever in a patient with low BMI is always significant and can indicate infection, with negative consequences because even minor episodes of sepsis can have a fatal outcome. Other signs present could be pale conjunctives, dry tongue and teguments, muscular weakness, peripheral edema in the context of low-level albumin, hand calluses after self-induced vomiting. It is not uncommon that patients present constipation, as a paradox effect of withdrawing the laxatives that were used for long periods of time in very high doses [31].

#### **6. Making a diagnosis of eating disorder**

The ICD-11 restructured the chapter of feeding and eating disorders guided by the principles of more clinical utility and relevance around the world, after 25 years of research and evidence based knowledge. The disorders included in this chapter are not better explained by other health problems, developmentally conditions or cultural context. Moreover, two previous distinct conditions were united in one single block named feeding and eating disorders that combines abnormal eating patterns associated with fear of gaining weight, body image and feeding behaviors that imply limited food intake, eating non-edible substances, or voluntary regurgitation of foods that have been eaten. We could say that this grouping decision enhances the clinical importance of feeding problems during infancy and childhood [32].

The ICD-11 guidelines for Pica have not been changed in a substantial way from the previous version of ICD. Pica is still characterized by a frequent and regular ingestion of non-nutritive substances, like different objects or materials, to a persistent and severe degree that requires special clinical attention, in a subject capable to distinguish between substances that can and cannot be eaten. This type of behavior has severe risks on the health and functioning system of an individual [31, 32].

For the rumination and regurgitation disorder the ICD-11 guidelines are almost the same as in the ICD-10. The main symptoms of the disorder need to be frequent as several times per week and present over a sustained period of at least several weeks. Characteristic symptoms that appear in an individual that reached the age of 2 are represented by regurgitation of food that was previous swallowed or the food that was brought up in the mouth could be re-chewed, re-swallowed or spat out [33].

A new ICD-11 diagnosis is avoidant-restrictive food intake disorder, characterized by a very low and insufficient amount or variety of food in order to supply an adequate level of energy or demands. This course of restriction causes weight loss and nutritional deficiencies but without a preoccupation of body weight and shape [33].

For Anorexia nervosa, the major features of the disorder remained unchanged in the ICD-11, such as a low body weight for an individual's height, age and developmental phase without a better explanation of another condition. The low weight

**49**

*Feeding and Eating Disorders*

18.5 and 14.0 kg/m2

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

is defined by a body mass index under 18.5 km/m2

weight and requires a BMI below 14.0 kg/m2

the regular compensatory behaviors [35].

rather the quantity ingested [36].

in children or adolescents, but these should be used as general aspects of reference permitting in some circumstance to diagnose anorexia nervosa at higher levels of weight. A detailed specification was added to anorexia as a severity qualifier indicating that the level of underweight status can influence the prognosis by other health complications determining a high mortality risk or a poorer outcome. This classification consists in significantly low body weight; defined as a BMI between

percentile in children. The next severity step is named as dangerously low body

loss weight so that anorexia nervosa diagnosis can be confirmed [32–34].

Bulimia nervosa in the ICD-11 remains characterized by binge eating episodes and compensatory behaviors to prevent weight gain but, different from anorexia nervosa, the patient is not underweight even if they are preoccupied by body shape image. A change in the frequency of the binge eating episodes was made by reducing them to once a week or more over a period of at least 1 month. Also, the time criteria have been shortened admitting the importance of receiving clinical care without any further delay. In parallel, for DSM-5 the time criteria include a period of at least 3 months. A binge eating episode represents a distinct period when an individual has no control over the eating or the amount of food intake. The common type of bulimia is the one without purging but with severe fasting or physical exercises and can be difficult to differentiate from binge eating disorder based solely on

A new diagnosis was added to ICD-11, named binge eating disorder, separated by the other eating disorders as a disturbance characterized by recurrent binge eating episodes accompanied by negative emotions and severe distress, without compensatory behaviors to prevent weight gain. This category was previously described in the Appendix of DSM-IV and now forms a new diagnosis in the DSM-5. To assume a correct diagnosis according to DSM-5, 3 out of 5 additional features have to be present, like: eating faster than normal; eating even if the patient does not feel hungry; eating until he feels uncomfortably full; the food intake is done in solitude; and negative emotions such as guilt, disgust or depression can follow the overeating. An important aspect is that ICD-11 guidelines do not require for the binge eating episodes an objective evaluation of the amount of food eaten but suggests the importance of the subjective experience of losing control over eating

While both bulimia nervosa and binge eating disorder associate marked distress

in the ICD-11 criteria, the DSM-5 requires marked distress just for binge eating disorder and not in the case of bulimia nervosa. A possible explanation for these differences between the two diagnostic categories would be the presence of the weight-compensatory behaviors that we can assume to reflect severe distress. In ICD-11 disturbances in body shape are required for anorexia and bulimia nervosa;

percentile. Another important aspect in the ICD-11 is the qualifier anorexia nervosa in recovery with normal body weight, providing a solution for those patients that have regained weight but still need special attention and care. Despite the DSM-5 classifications, ICD-11 emphasizes the behavior patterns (restricting pattern and binge-purge pattern) that are weight related and used by patients in order to lose more weight. In both classification systems, physical symptoms such as amenorrhea, osteopenia are frequent consequences of food restriction, they still occur but they are no longer considered as one of the main criteria for diagnosis. Also, the ICD-11 and DSM-5 do not include as mandatory the presence of a reported fear about gaining weight, considering this symptom as a more culturally based belief. On the other hand, there is a need of modified normal behavior in order to prevent

for adult subjects and between the fifth percentile and the 0.3

or less than the fifth percentile

for adults and for children less than 0.3

#### *Feeding and Eating Disorders DOI: http://dx.doi.org/10.5772/intechopen.92218*

*Neurological and Mental Disorders*

plasma ferritin, folate, and B12 vitamin [30].

**6. Making a diagnosis of eating disorder**

with a pulse over 100 bpm suggesting infection or dehydration [29]. Also, basic screening is necessary. A full blood cell count has to be done, biochemical assays such as transaminase to evaluate liver function, creatinine and urea for determining renal function. Electrolytes abnormalities are common and need to be measured to exclude hyponatremia after an excessive water intake, hypokalemia in the context of excessive purging, or hypocalcaemia, hypomagnesaemia that can indicate the improper use of laxatives. Thyroid function should be checked together with

Body temperature frequently drops under 36°C in anorexic patients, who voluntary induce hypothermia in order to start shivering, consume energy and lose some more weight. Fever in a patient with low BMI is always significant and can indicate infection, with negative consequences because even minor episodes of sepsis can have a fatal outcome. Other signs present could be pale conjunctives, dry tongue and teguments, muscular weakness, peripheral edema in the context of low-level albumin, hand calluses after self-induced vomiting. It is not uncommon that patients present constipation, as a paradox effect of withdrawing the laxatives

The ICD-11 restructured the chapter of feeding and eating disorders guided by the principles of more clinical utility and relevance around the world, after 25 years of research and evidence based knowledge. The disorders included in this chapter are not better explained by other health problems, developmentally conditions or cultural context. Moreover, two previous distinct conditions were united in one single block named feeding and eating disorders that combines abnormal eating patterns associated with fear of gaining weight, body image and feeding behaviors that imply limited food intake, eating non-edible substances, or voluntary regurgitation of foods that have been eaten. We could say that this grouping decision enhances the clinical importance of feeding problems during infancy and

The ICD-11 guidelines for Pica have not been changed in a substantial way from the previous version of ICD. Pica is still characterized by a frequent and regular ingestion of non-nutritive substances, like different objects or materials, to a persistent and severe degree that requires special clinical attention, in a subject capable to distinguish between substances that can and cannot be eaten. This type of behavior has severe risks on the health and functioning system of an individual [31, 32]. For the rumination and regurgitation disorder the ICD-11 guidelines are almost the same as in the ICD-10. The main symptoms of the disorder need to be frequent as several times per week and present over a sustained period of at least several weeks. Characteristic symptoms that appear in an individual that reached the age of 2 are represented by regurgitation of food that was previous swallowed or the food that was brought up in the mouth could be re-chewed, re-swallowed or

A new ICD-11 diagnosis is avoidant-restrictive food intake disorder, characterized by a very low and insufficient amount or variety of food in order to supply an adequate level of energy or demands. This course of restriction causes weight loss and nutritional deficiencies but without a preoccupation of body weight and

For Anorexia nervosa, the major features of the disorder remained unchanged in the ICD-11, such as a low body weight for an individual's height, age and developmental phase without a better explanation of another condition. The low weight

that were used for long periods of time in very high doses [31].

**48**

childhood [32].

spat out [33].

shape [33].

is defined by a body mass index under 18.5 km/m2 or less than the fifth percentile in children or adolescents, but these should be used as general aspects of reference permitting in some circumstance to diagnose anorexia nervosa at higher levels of weight. A detailed specification was added to anorexia as a severity qualifier indicating that the level of underweight status can influence the prognosis by other health complications determining a high mortality risk or a poorer outcome. This classification consists in significantly low body weight; defined as a BMI between 18.5 and 14.0 kg/m2 for adult subjects and between the fifth percentile and the 0.3 percentile in children. The next severity step is named as dangerously low body weight and requires a BMI below 14.0 kg/m2 for adults and for children less than 0.3 percentile. Another important aspect in the ICD-11 is the qualifier anorexia nervosa in recovery with normal body weight, providing a solution for those patients that have regained weight but still need special attention and care. Despite the DSM-5 classifications, ICD-11 emphasizes the behavior patterns (restricting pattern and binge-purge pattern) that are weight related and used by patients in order to lose more weight. In both classification systems, physical symptoms such as amenorrhea, osteopenia are frequent consequences of food restriction, they still occur but they are no longer considered as one of the main criteria for diagnosis. Also, the ICD-11 and DSM-5 do not include as mandatory the presence of a reported fear about gaining weight, considering this symptom as a more culturally based belief. On the other hand, there is a need of modified normal behavior in order to prevent loss weight so that anorexia nervosa diagnosis can be confirmed [32–34].

Bulimia nervosa in the ICD-11 remains characterized by binge eating episodes and compensatory behaviors to prevent weight gain but, different from anorexia nervosa, the patient is not underweight even if they are preoccupied by body shape image. A change in the frequency of the binge eating episodes was made by reducing them to once a week or more over a period of at least 1 month. Also, the time criteria have been shortened admitting the importance of receiving clinical care without any further delay. In parallel, for DSM-5 the time criteria include a period of at least 3 months. A binge eating episode represents a distinct period when an individual has no control over the eating or the amount of food intake. The common type of bulimia is the one without purging but with severe fasting or physical exercises and can be difficult to differentiate from binge eating disorder based solely on the regular compensatory behaviors [35].

A new diagnosis was added to ICD-11, named binge eating disorder, separated by the other eating disorders as a disturbance characterized by recurrent binge eating episodes accompanied by negative emotions and severe distress, without compensatory behaviors to prevent weight gain. This category was previously described in the Appendix of DSM-IV and now forms a new diagnosis in the DSM-5. To assume a correct diagnosis according to DSM-5, 3 out of 5 additional features have to be present, like: eating faster than normal; eating even if the patient does not feel hungry; eating until he feels uncomfortably full; the food intake is done in solitude; and negative emotions such as guilt, disgust or depression can follow the overeating. An important aspect is that ICD-11 guidelines do not require for the binge eating episodes an objective evaluation of the amount of food eaten but suggests the importance of the subjective experience of losing control over eating rather the quantity ingested [36].

While both bulimia nervosa and binge eating disorder associate marked distress in the ICD-11 criteria, the DSM-5 requires marked distress just for binge eating disorder and not in the case of bulimia nervosa. A possible explanation for these differences between the two diagnostic categories would be the presence of the weight-compensatory behaviors that we can assume to reflect severe distress. In ICD-11 disturbances in body shape are required for anorexia and bulimia nervosa;

self-body image concerns can be present in the binge eating disorder or avoidantrestrictive food intake disorder but are not necessary criteria. All in all, the new changes have the purpose to broaden the diagnostic process and facilitate clinical practice with the disadvantage of over diagnosing but also with respect to the course of life evolution [37].

If the criteria of behavior frequency are not fulfilled or other symptoms are considered sub-threshold, those eating disorders are classified in the DSM-5 as unspecified feeding and eating disorders, and in the ICD-11 as poorly specified other feeding and eating disorder [34, 37].

#### **7. Differential diagnosis**

Eating disorders must be medically assessed in order to establish if present physical conditions are consequences of the mental illness or different somatic health problems. This strategy allows developing an integrated management plan, because both problems need proper evaluation and treatment and can impact recovery or the quality of life [38].

The most common symptoms in anorexia nervosa are the fear of gaining weight and the excessive preoccupation of being overweight or fat. Despite the fact that they are malnourished, patients try to lose even more weight. In contrast, many gastrointestinal illnesses have as a central symptom the weight loss and in this situation the patient is worried about the loss and tries to regain weight. The main two illnesses with this symptomatology are coeliac disease and inflammatory bowel disease. More family members can be affected by these diseases, but such family predisposition can be present for eating disorders too [39].

On the other hand, functional gastrointestinal disorders cam mimic an eating disorder, but usually they do not associate weight loss and have a long past evolution in the patient's history. Such frequently reported diseases are the irritable bowel syndrome and the non-ulcer dyspepsia, also common in patients with diagnose of eating disorder. Food intolerance and allergies can simultaneously be present in a patient with eating disorders, but in this scenario it is more difficult to precisely discriminate between the two conditions [40]. The loss of appetite is a very common symptom, but nonspecific, in both mental and physical disorders. It can associate with weight lost and needs more investigating. In eating disorders, patients do not lose their appetite, the restriction from food intake has a voluntary component, that is not present in organic disorders, were the loss of appetite is without effort and involuntary. On the other hand, compulsive eating with an increased level of appetite can be present in Prader-Willi syndrome, craniopharyngioma, tumors of the hypothalamus or recovery from acute illnesses. This symptom is characteristic in bulimia nervosa or the binge purge subtype of anorexia [41]. Dysphagia is considered an alarming symptom in old age patients, and needs endoscopy or barium passage, malignancy strictures or achalasia are usually suspected. Other gastrointestinal symptoms that are commonly present include odynophagia, nausea, vomiting, hematemesis or melena, abdominal pain, constipation, diarrhea. Odynophagia described as pain when swallowing can be present in a reflux esophagitis or esophageal candida. Vomiting is a very unspecific symptom usually associated with nausea that can have different causes such as inflammatory bowel disease, side effects of different drugs, a high intracranial pressure, pyloric stenosis, gastro-paresis, but in these circumstances a voluntary control is not present as in eating disorders and it is not hidden [42]. Hematemesis or melena can represent a medical emergency, but frequently represent a consequence of purging and vomiting, with the development of Mallory Weiss tears. For the abdominal pain the doctor should establish

**51**

m2

will lead to death [44].

*Feeding and Eating Disorders*

ulcerative colitis [43].

years or early adulthood [43].

be placed in a chronological order.

**8. Management of eating disorders**

tion phase much easier. Patients with a BMI over 16 kg/m2

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

the level of intensity, quality and localization of the pain in order to differentiate a peptic ulcer, gallstones, pancreatitis or appendicitis. Constipation, diarrhea, and rectal bleeding are symptoms that need to be integrated with other factors and the most important aspect is the change in bowel habit that can imply Crohn's disease or

The age of onset can be a very important clue. Usually, organic conditions, in special malignant illnesses that can manifest with weight loss, become more frequent with old age. If symptoms appear over 50 years, appropriate investigations are required. Moreover, the onset of eating disorders is identified in the teenage

In order to establish a diagnosis of an eating disorder the patient should be physically examined, the mental state evaluation should be done, all of these supported by a detailed medical history, family history and social context. All symptoms must

International guidelines recommend psycho-behavior therapy for all eating disorders, which can be applied in a form of outpatient care, when the treatment is accepted and the patient accepts to cooperate, with major beneficial effects, being more cost-effective, reducing hospitalizations, making patients feel more secure in their own environment, maintaining social contact with friends and family members, being able to perform other pleasant activities and making the rehabilita-

binge purge syndrome are usually treated in outpatient or day care units because the risks are less serious on physical harm and this form of outpatient context has been proved to be highly effective [44]. On the other hand, for more severe forms, when patients' symptoms are not improving with home treatment or the patients' physical status is unstable (weight is rapidly diminishing, the BMI is under 14 kg/

, low pulse, blood pressure, body temperature decreasing or fever being present, difficulty in performing the basic test of physical strength) more restrictive measures must be taken in a partial or day admission, or even a compulsory treatment would be necessary in order for the patient to improve physical and mentally but also, to limit potential harm behavior [45]. Anorexic patients in general do not want to die, but it is needed to understand the psychological drive of an anorexic patient who has an extreme fear of gaining weight, who is unable to rationally see that their physical state has become critical, and if the weight will continue to drop the result

It is highly recommended for these patients to be treated by a multi-disciplinary

team with a minimum of a psychological therapist and a family doctor, but in hospital care additional support is required as a registered dietician, specialist physician, psychiatrist, nurses, physiotherapist, occupational therapist and social worker [46]. Nurses and other medical staff represent a key element in the management treatment approach by limiting mobility, imposing bed rest, monitoring fluid balance and physical symptoms (pulse, blood pressure, temperature), supervising mealtimes (observation for at least 1 h after eating), showers, toilets (patients being alone can consider a perfect opportunity to engage in behaviors such as purging, excessive physical exercises or water loading for a false weight gain). Even with the risk of some saying these rules are unethical; protocols like this can avoid numerous unwanted behaviors done by patients in the purpose of resisting the weight gain and destroying the process of recovery. In the context of bed resting for an easier and closer observation it is important to start prophylaxis for deep vein thrombosis with

, with bulimia nervosa or

#### *Feeding and Eating Disorders DOI: http://dx.doi.org/10.5772/intechopen.92218*

*Neurological and Mental Disorders*

other feeding and eating disorder [34, 37].

of life evolution [37].

**7. Differential diagnosis**

recovery or the quality of life [38].

predisposition can be present for eating disorders too [39].

self-body image concerns can be present in the binge eating disorder or avoidantrestrictive food intake disorder but are not necessary criteria. All in all, the new changes have the purpose to broaden the diagnostic process and facilitate clinical practice with the disadvantage of over diagnosing but also with respect to the course

If the criteria of behavior frequency are not fulfilled or other symptoms are considered sub-threshold, those eating disorders are classified in the DSM-5 as unspecified feeding and eating disorders, and in the ICD-11 as poorly specified

Eating disorders must be medically assessed in order to establish if present physical conditions are consequences of the mental illness or different somatic health problems. This strategy allows developing an integrated management plan, because both problems need proper evaluation and treatment and can impact

The most common symptoms in anorexia nervosa are the fear of gaining weight and the excessive preoccupation of being overweight or fat. Despite the fact that they are malnourished, patients try to lose even more weight. In contrast, many gastrointestinal illnesses have as a central symptom the weight loss and in this situation the patient is worried about the loss and tries to regain weight. The main two illnesses with this symptomatology are coeliac disease and inflammatory bowel disease. More family members can be affected by these diseases, but such family

On the other hand, functional gastrointestinal disorders cam mimic an eating disorder, but usually they do not associate weight loss and have a long past evolution in the patient's history. Such frequently reported diseases are the irritable bowel syndrome and the non-ulcer dyspepsia, also common in patients with diagnose of eating disorder. Food intolerance and allergies can simultaneously be present in a patient with eating disorders, but in this scenario it is more difficult to precisely discriminate between the two conditions [40]. The loss of appetite is a very common symptom, but nonspecific, in both mental and physical disorders. It can associate with weight lost and needs more investigating. In eating disorders, patients do not lose their appetite, the restriction from food intake has a voluntary component, that is not present in organic disorders, were the loss of appetite is without effort and involuntary. On the other hand, compulsive eating with an increased level of appetite can be present in Prader-Willi syndrome, craniopharyngioma, tumors of the hypothalamus or recovery from acute illnesses. This symptom is characteristic in bulimia nervosa or the binge purge subtype of anorexia [41]. Dysphagia is considered an alarming symptom in old age patients, and needs endoscopy or barium passage, malignancy strictures or achalasia are usually suspected. Other gastrointestinal symptoms that are commonly present include odynophagia, nausea, vomiting, hematemesis or melena, abdominal pain, constipation, diarrhea. Odynophagia described as pain when swallowing can be present in a reflux esophagitis or esophageal candida. Vomiting is a very unspecific symptom usually associated with nausea that can have different causes such as inflammatory bowel disease, side effects of different drugs, a high intracranial pressure, pyloric stenosis, gastro-paresis, but in these circumstances a voluntary control is not present as in eating disorders and it is not hidden [42]. Hematemesis or melena can represent a medical emergency, but frequently represent a consequence of purging and vomiting, with the development of Mallory Weiss tears. For the abdominal pain the doctor should establish

**50**

the level of intensity, quality and localization of the pain in order to differentiate a peptic ulcer, gallstones, pancreatitis or appendicitis. Constipation, diarrhea, and rectal bleeding are symptoms that need to be integrated with other factors and the most important aspect is the change in bowel habit that can imply Crohn's disease or ulcerative colitis [43].

The age of onset can be a very important clue. Usually, organic conditions, in special malignant illnesses that can manifest with weight loss, become more frequent with old age. If symptoms appear over 50 years, appropriate investigations are required. Moreover, the onset of eating disorders is identified in the teenage years or early adulthood [43].

In order to establish a diagnosis of an eating disorder the patient should be physically examined, the mental state evaluation should be done, all of these supported by a detailed medical history, family history and social context. All symptoms must be placed in a chronological order.

#### **8. Management of eating disorders**

International guidelines recommend psycho-behavior therapy for all eating disorders, which can be applied in a form of outpatient care, when the treatment is accepted and the patient accepts to cooperate, with major beneficial effects, being more cost-effective, reducing hospitalizations, making patients feel more secure in their own environment, maintaining social contact with friends and family members, being able to perform other pleasant activities and making the rehabilitation phase much easier. Patients with a BMI over 16 kg/m2 , with bulimia nervosa or binge purge syndrome are usually treated in outpatient or day care units because the risks are less serious on physical harm and this form of outpatient context has been proved to be highly effective [44]. On the other hand, for more severe forms, when patients' symptoms are not improving with home treatment or the patients' physical status is unstable (weight is rapidly diminishing, the BMI is under 14 kg/ m2 , low pulse, blood pressure, body temperature decreasing or fever being present, difficulty in performing the basic test of physical strength) more restrictive measures must be taken in a partial or day admission, or even a compulsory treatment would be necessary in order for the patient to improve physical and mentally but also, to limit potential harm behavior [45]. Anorexic patients in general do not want to die, but it is needed to understand the psychological drive of an anorexic patient who has an extreme fear of gaining weight, who is unable to rationally see that their physical state has become critical, and if the weight will continue to drop the result will lead to death [44].

It is highly recommended for these patients to be treated by a multi-disciplinary team with a minimum of a psychological therapist and a family doctor, but in hospital care additional support is required as a registered dietician, specialist physician, psychiatrist, nurses, physiotherapist, occupational therapist and social worker [46]. Nurses and other medical staff represent a key element in the management treatment approach by limiting mobility, imposing bed rest, monitoring fluid balance and physical symptoms (pulse, blood pressure, temperature), supervising mealtimes (observation for at least 1 h after eating), showers, toilets (patients being alone can consider a perfect opportunity to engage in behaviors such as purging, excessive physical exercises or water loading for a false weight gain). Even with the risk of some saying these rules are unethical; protocols like this can avoid numerous unwanted behaviors done by patients in the purpose of resisting the weight gain and destroying the process of recovery. In the context of bed resting for an easier and closer observation it is important to start prophylaxis for deep vein thrombosis with

low molecular weight heparin [47]. Also, clothes need to be checked because they can represent means for falsifying weight or transport regurgitated food. Dieticians are also important for the safe management of patients with eating disorders. They need to be consulted for the risk of re-feeding syndrome, must establish a meal plan for proper nutritional requirements, to include all nutrients, carbohydrates, proteins, fats, vitamins and all kinds of minerals, to use supplements if the case imposes, and monitor weight gaining in a correct pace, and also, on the long term, to provide proper education for a balanced nutrition plan and teach patients how to prepare their meals and eat adequately in social situations [46].

The management of over activity can be treated firstly by providing psychoeducation about the advantages and disadvantages of this behavior and to discourage exercise. Also, relaxation and distractions techniques can be helpful, the use of wheelchairs to reduce the level of energy spent, administer Olanzapine with a good effect on the compulsive behavior, providing a calm and warm environment, with a permanent supervision from medical staff [48].

Treatment goals address numerous aspects such as nutritional, physical, social and mental health comorbidities. Some studies were made on healthy subjects, who voluntarily agreed to be starved, and the effect of this demonstrated that even in normal subjects thought processes were slowed, executive functions were impaired, with decision making disturbances, and personality traits accentuated in a manner that persons were more paranoid, depressed or became psychotic. The majority of these symptoms were reversed by re-feeding treatment in normal individuals and similarities were observed for anorexic patients, who had an improvement in thinking, mood stability and improved the engagement level for psychotherapy [49].

For malnourished patients re-feeding may represent the only solution for surviving. It has to be initiated promptly with benefits on the physical strength, cerebral function. It restores the reduced size of internal organs, heart, gut and their functions, offers a better functioning of the immune system, patients being less susceptible for infections. All of these outcomes appear after a slow process, because the body needs to readapt to the increased availability of calories and nutrients [50]. If the patients have a very low BMI, under 16 kg/m2 , or had a rapid loss weight within the last 3–6 months of over 15% of the body weight, had little nutritional intake for more than 10 days or have low levels of potassium, phosphate, magnesium prior to the re-feeding, they are at risk of developing a re-feeding syndrome, according to the NICE guidelines [51]. The re-feeding syndrome can be defined as a consequence of trying to re-establish the normal weight of a very malnourished patient. During this phase, the maximal risk is within 72 h and implies potentially fatal shifts in fluids and electrolytes. The characteristic biochemical abnormality is the hypophosphatemia, but hypokalemia and hypomagnesaemia can also occur. NICE recommends starting re-feeding process at 5 kcal/kg/24 h for those with severe anorexia nervosa, through a nasogastric re-feeding tube and progressively increasing the rate of re-feeding to the target calorie intake over the next 4–7 days. Other studies showed that higher initial re-feeding rates can be applied such as 15 or 20 kcal/kg/ 24 h, with or without the association of re-feeding syndrome [52].

In order to avoid this kind of situations the patient has to be admitted in special medical units with experience in re-feeding syndrome, to monitor the blood chemistry twice a day, start with caution and increase quickly if the patient tolerates well. A particular aspect is to start giving thiamine before feeding starts, and to continue with it at least 10 days in order to overcome the development of Wernicke's encephalopathy or Korsakoff syndrome. Hypophosphatemia can have fatal effect through numerous clinical features such as cardiac failure, arrhythmias, seizures, tremor, rhabdomyolysis, and respiratory failure. Hypomagnesaemia can also occur and complicate the feeding treatment by cardiac arrhythmia, hypertension crises,

**53**

*Feeding and Eating Disorders*

cardiomyopathy [53, 54].

oral intake [55].

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

tremor, tetany, confusion, seizures and abdominal pain. Hypokalemia can appear as a consequence of staring to feed the anorexic patient, but more common it is present in patients with binge-purge subtype because of vomiting or induced laxative diarrhea. All of these electrolyte deficiencies must be treated properly to offer a safe outcome. Other complications that can occur during re-feeding are elevated transaminase levels with liver failure, coagulation problems, acute tubular renal necrosis, tubular renal nephritis, cardiac Torsade du Pointes, arrhythmias, prolonged QTc,

If the patients is in a severe state for the re-feeding process doctors have to decide if an enteral tube feeding is required. For this intervention training and experience is need, because the gut wall in malnourished patients is extremely thin and there is the risk of rupture, a lethal complication. Also after passing the tube, the safety position must be checked before it is used. In order to confirm the placement of the tube, gastric fluid can be aspirated, and the level of acidity can be determined, or an X-ray might be required. Gastrostomy tubes are not advisable to use, they need an endoscopic or radiologic approach, with the risk of peritonitis or other infections. Feeding through a tube is just a temporary solution, as part of an integrated plan, and patients need to be responsible and slowly introduce a full

For osteopenia the recommended treatment is weight restoration and a normalization of the endocrine hormones. Also hormones substitution with transdermal estrogen, analogue of parathyroid hormone, bisphosphonates, raloxifene and

Psychotherapy should be the treatment of choice for all eating disorders. The number of sessions required is different in each eating disorder type. In the case of anorexia nervosa no specific psychotherapy has shown clear superiority, but the number of sessions required is the highest, with an average of 40. Adolescents with anorexia nervosa have better outcomes after family therapy. For bulimia nervosa and binge eating disorder psychotherapy should be offered as a first line treatment, especially cognitive behavior therapy, or as an alternative interpersonal psychotherapy, psychodynamic, or family-based therapy in children and adolescent with bulimia nervosa. Usually the number of sessions required is less for bulimia and

Pharmacological therapies with positive results in controlled trials in eating disorders are second generation of antipsychotics and antidepressants. For anorexia nervosa olanzapine had the most beneficial effects, in the case of bulimia nervosa and binge eating disorder Fluoxetine showed a good outcome, with a small effect from Lisdexamfetamine for binge eating disorder and Mirtazapine for avoidant

Eating disorders characterized by low weight associate high morbidity and mortality rates. A follow-up study which monitored hospitalized patients with anorexia nervosa reported an average life expectancy of 39 years. Studies showed that 1/3 of patients suffering from anorexia nervosa tend to have a full recovery, in same percentage patients have just a partial recovery, and approximately 1/3 will have a chronic evolution or die. On a more optimistic point of view, a full recovery has been shown to be possible but with early intervention plan and sustained treatment

In general the prognosis for bulimia nervosa is good with treatment and assistance, but if the patient associate low self-esteem or different forms of personality

denosumab drugs can be prescribed in this case [56].

binge eating disorder, with a medium of 20 weeks [57, 58].

restrictive eating disorder [59, 60].

over a medium of almost 7 to 9 years [61].

**9. Evolution and prognosis**

#### *Feeding and Eating Disorders DOI: http://dx.doi.org/10.5772/intechopen.92218*

*Neurological and Mental Disorders*

low molecular weight heparin [47]. Also, clothes need to be checked because they can represent means for falsifying weight or transport regurgitated food. Dieticians are also important for the safe management of patients with eating disorders. They need to be consulted for the risk of re-feeding syndrome, must establish a meal plan for proper nutritional requirements, to include all nutrients, carbohydrates, proteins, fats, vitamins and all kinds of minerals, to use supplements if the case imposes, and monitor weight gaining in a correct pace, and also, on the long term, to provide proper education for a balanced nutrition plan and teach patients how to

The management of over activity can be treated firstly by providing psychoeducation about the advantages and disadvantages of this behavior and to discourage exercise. Also, relaxation and distractions techniques can be helpful, the use of wheelchairs to reduce the level of energy spent, administer Olanzapine with a good effect on the compulsive behavior, providing a calm and warm environment, with a

Treatment goals address numerous aspects such as nutritional, physical, social and mental health comorbidities. Some studies were made on healthy subjects, who voluntarily agreed to be starved, and the effect of this demonstrated that even in normal subjects thought processes were slowed, executive functions were impaired, with decision making disturbances, and personality traits accentuated in a manner that persons were more paranoid, depressed or became psychotic. The majority of these symptoms were reversed by re-feeding treatment in normal individuals and similarities were observed for anorexic patients, who had an improvement in thinking, mood stability and improved the engagement level for psychotherapy [49].

For malnourished patients re-feeding may represent the only solution for surviving. It has to be initiated promptly with benefits on the physical strength, cerebral function. It restores the reduced size of internal organs, heart, gut and their functions, offers a better functioning of the immune system, patients being less susceptible for infections. All of these outcomes appear after a slow process, because the body needs to readapt to the increased availability of calories and nutrients [50]. If

the last 3–6 months of over 15% of the body weight, had little nutritional intake for more than 10 days or have low levels of potassium, phosphate, magnesium prior to the re-feeding, they are at risk of developing a re-feeding syndrome, according to the NICE guidelines [51]. The re-feeding syndrome can be defined as a consequence of trying to re-establish the normal weight of a very malnourished patient. During this phase, the maximal risk is within 72 h and implies potentially fatal shifts in fluids and electrolytes. The characteristic biochemical abnormality is the hypophosphatemia, but hypokalemia and hypomagnesaemia can also occur. NICE recommends starting re-feeding process at 5 kcal/kg/24 h for those with severe anorexia nervosa, through a nasogastric re-feeding tube and progressively increasing the rate of re-feeding to the target calorie intake over the next 4–7 days. Other studies showed that higher initial re-feeding rates can be applied such as 15 or 20 kcal/kg/

In order to avoid this kind of situations the patient has to be admitted in special medical units with experience in re-feeding syndrome, to monitor the blood chemistry twice a day, start with caution and increase quickly if the patient tolerates well. A particular aspect is to start giving thiamine before feeding starts, and to continue with it at least 10 days in order to overcome the development of Wernicke's encephalopathy or Korsakoff syndrome. Hypophosphatemia can have fatal effect through numerous clinical features such as cardiac failure, arrhythmias, seizures, tremor, rhabdomyolysis, and respiratory failure. Hypomagnesaemia can also occur and complicate the feeding treatment by cardiac arrhythmia, hypertension crises,

24 h, with or without the association of re-feeding syndrome [52].

, or had a rapid loss weight within

prepare their meals and eat adequately in social situations [46].

permanent supervision from medical staff [48].

the patients have a very low BMI, under 16 kg/m2

**52**

tremor, tetany, confusion, seizures and abdominal pain. Hypokalemia can appear as a consequence of staring to feed the anorexic patient, but more common it is present in patients with binge-purge subtype because of vomiting or induced laxative diarrhea. All of these electrolyte deficiencies must be treated properly to offer a safe outcome. Other complications that can occur during re-feeding are elevated transaminase levels with liver failure, coagulation problems, acute tubular renal necrosis, tubular renal nephritis, cardiac Torsade du Pointes, arrhythmias, prolonged QTc, cardiomyopathy [53, 54].

If the patients is in a severe state for the re-feeding process doctors have to decide if an enteral tube feeding is required. For this intervention training and experience is need, because the gut wall in malnourished patients is extremely thin and there is the risk of rupture, a lethal complication. Also after passing the tube, the safety position must be checked before it is used. In order to confirm the placement of the tube, gastric fluid can be aspirated, and the level of acidity can be determined, or an X-ray might be required. Gastrostomy tubes are not advisable to use, they need an endoscopic or radiologic approach, with the risk of peritonitis or other infections. Feeding through a tube is just a temporary solution, as part of an integrated plan, and patients need to be responsible and slowly introduce a full oral intake [55].

For osteopenia the recommended treatment is weight restoration and a normalization of the endocrine hormones. Also hormones substitution with transdermal estrogen, analogue of parathyroid hormone, bisphosphonates, raloxifene and denosumab drugs can be prescribed in this case [56].

Psychotherapy should be the treatment of choice for all eating disorders. The number of sessions required is different in each eating disorder type. In the case of anorexia nervosa no specific psychotherapy has shown clear superiority, but the number of sessions required is the highest, with an average of 40. Adolescents with anorexia nervosa have better outcomes after family therapy. For bulimia nervosa and binge eating disorder psychotherapy should be offered as a first line treatment, especially cognitive behavior therapy, or as an alternative interpersonal psychotherapy, psychodynamic, or family-based therapy in children and adolescent with bulimia nervosa. Usually the number of sessions required is less for bulimia and binge eating disorder, with a medium of 20 weeks [57, 58].

Pharmacological therapies with positive results in controlled trials in eating disorders are second generation of antipsychotics and antidepressants. For anorexia nervosa olanzapine had the most beneficial effects, in the case of bulimia nervosa and binge eating disorder Fluoxetine showed a good outcome, with a small effect from Lisdexamfetamine for binge eating disorder and Mirtazapine for avoidant restrictive eating disorder [59, 60].

#### **9. Evolution and prognosis**

Eating disorders characterized by low weight associate high morbidity and mortality rates. A follow-up study which monitored hospitalized patients with anorexia nervosa reported an average life expectancy of 39 years. Studies showed that 1/3 of patients suffering from anorexia nervosa tend to have a full recovery, in same percentage patients have just a partial recovery, and approximately 1/3 will have a chronic evolution or die. On a more optimistic point of view, a full recovery has been shown to be possible but with early intervention plan and sustained treatment over a medium of almost 7 to 9 years [61].

In general the prognosis for bulimia nervosa is good with treatment and assistance, but if the patient associate low self-esteem or different forms of personality disorders these aspects can affect the outcome. Little is known about the prognosis in binge eating disorders or other eating and feeding disorders [62].

For all eating disorders, poor prognostic factors can be considered as: late onset, anxiety in the presence of others when eating, severe weight loss, association of other chronic disorders, difficulties in childhood for social adjustment, being a male, having conflicts with parents or friends, being present binge and purge behaviors, low motivational for change, shame or not having enough money for engaging in psychotherapies sessions, association of concomitant depressed mood and obsessive body imagine preoccupation. Better evolutions have been identified in adolescents than adults, but only in association with family psychotherapy making the majority of these patients partially recovered, with less episodes of relapse. Also, in the young group distribution an onset in adolescents have a much better prognosis than one in early childhood [62].

#### **10. Insight in eating disorders**

There is now a general agreement that insight is not an all-or-none phenomenon, but rather a complex, multidimensional concept in psychiatric disorders. It includes different components, like the ability of a patient to recognize the presence of a mental illness, the capacity to accept that some symptoms are pathological and are determined by a mental disorder, the awareness of illness's consequences and compliance with treatment [63].

Lack of insight has been largely demonstrated in schizophrenia, other psychoses and bipolar disorder [64–67]. DSM-5 included an "insight" specifier in OCD, body dysmorphic and hoarding disorder. Also, different levels of lack of insight, from good to absent, have been found in other psychiatric disorders, like depressive and anxiety disorders, specific and social phobias, Alzheimer disease and other neurocognitive disorders, eating disorders [68–71].

Patients with anorexia nervosa (AN) commonly lack insight, at least in the early stages of illness. This element will determine important difficulties in assessment, lack of compliance or avoidance of treatment, frequent relapses and also may limit the identification of eating disorders. These patients have distorted cognitions about body weight and shape and also, they are ambivalent regarding motivation to recover [72]. On the other hand, patients with bulimia nervosa (BN) have typically a bigger level of motivation to recover.

Until now there is not a disorder-specific scale for the assessment of insight in patients with eating disorders. Many researchers use SAI-ED (the Schedule for the Assessment of Insight for EDs), a short self-report questionnaire, which has only seven items. Even if the SAI-ED has not been fully validated, has a significant level of internal consistency [72].

#### **10.1 Factors associated with insight**

In their study evaluating the clinical insight in 193 patients with anorexia nervosa, Gorwood et al. observed that 88% of patients (171) had a high level of insight (SAI-ED total score > 4) and 12% of patients (22) had a poor insight (SAI-ED < 4).

The authors drew three important conclusions:

1.Insight was not improved in a vast majority of patients, even if they followed 4 months of specialized care and all clinical and cognitive markers improved.

**55**

*Feeding and Eating Disorders*

psychotherapy [72–76].

disorder (BID) [77].

**Conflict of interest**

was minimum BMI.

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

**11. Psychiatric comorbidities in eating disorders**

and personality or conduct disorder [77].

2.In this study, the only factor that has been demonstrated improving insight

Other studies revealed other factors correlated with insight (cognitive functions memory and executive functions), psychiatric and addictive comorbidities, associated personality disorders prescribed psychotropic drugs, social cognitions, use of

Beside comorbid somatic conditions of eating disorders (anemia, arteriosclerosis, hypertension, high cholesterol, high triglycerides, myocardial infarction, lung problems, stomach ulcer, Bowel problems, liver diseases, fibromyalgia, stroke, epilepsy or seizures, cancer, arthritis, osteoporosis, sleep problems), all three EDs (eating disorders) are associated with other psychiatric conditions, especially mood disorders, anxiety disorders, posttraumatic stress disorder, substance use disorder

Regarding mood disorders, most common associated with EDs are major depressive disorder, persistent depression, bipolar I [78]. Affective disorders, substance use disorders and anxiety disorders represent the most common predictive factors for suicide. Researchers have reported also that eating disorders are associated with suicide. The meta-analysis of Smith et al. [78], which included 2611 longitudinal studies, concluded that ED diagnosis is significantly associated with an increased risk for suicide attempt (SA) although the rate of SA varied considerably across studies [78]. In the group of patients with anorexia nervosa (AN), the rate of SA was between 3 and 20% [79]; in bulimia nervosa patients (BN), the rate ranged between 25 and 35% [79]; and in BED patients, the rate was 12.5% [78] and 20.8% when combining all EDs [80]. In the study of Udo et al., which included 36,171 respondents in the Third National Epidemiological Survey on Alcohol and Related Conditions (NESARC-III), the prevalence of suicide attempts was 24.8% for AN, 15.5% for anorexia nervosa-restricted type (AN-R), 44.1% for anorexia nervosa binge/purge type (AN-BP), 31.4% for bulimia nervosa, and 22.9% for binge-eating

Regarding anxiety disorders, most common associated with eating disorders are panic disorder, social anxiety disorder, specific phobias and general anxiety disorder [78]. The association between social anxiety and EDs could be a part of a wider socio-emotional phenotype which it is considered to contribute to the development and maintenance of EDs. SA may be a risk factor for ED, or SA may be secondary to

Abuse of substances is common in EDs, the lifetime prevalence being estimated between 23 and 37% [82]. Tobacco, caffeine and alcohol were the most prevalent SUD in the study of Bahji et al., being followed by cannabis and cocaine [83, 84]. Between axis II DSM diagnoses, most common comorbidities in ED are antisocial, borderline and schizotypal personality disorders and conduct disorders [78].

the ED, as a consequence of ED psychopathology or malnutrition [81].

The authors declare that they have no conflict of interest.

3.Premorbid IQ was highly associated with the level of baseline insight.

*Neurological and Mental Disorders*

prognosis than one in early childhood [62].

**10. Insight in eating disorders**

compliance with treatment [63].

cognitive disorders, eating disorders [68–71].

a bigger level of motivation to recover.

**10.1 Factors associated with insight**

The authors drew three important conclusions:

of internal consistency [72].

disorders these aspects can affect the outcome. Little is known about the prognosis

For all eating disorders, poor prognostic factors can be considered as: late onset, anxiety in the presence of others when eating, severe weight loss, association of other chronic disorders, difficulties in childhood for social adjustment, being a male, having conflicts with parents or friends, being present binge and purge behaviors, low motivational for change, shame or not having enough money for engaging in psychotherapies sessions, association of concomitant depressed mood and obsessive body imagine preoccupation. Better evolutions have been identified in adolescents than adults, but only in association with family psychotherapy making the majority of these patients partially recovered, with less episodes of relapse. Also, in the young group distribution an onset in adolescents have a much better

There is now a general agreement that insight is not an all-or-none phenomenon, but rather a complex, multidimensional concept in psychiatric disorders. It includes different components, like the ability of a patient to recognize the presence of a mental illness, the capacity to accept that some symptoms are pathological and are determined by a mental disorder, the awareness of illness's consequences and

Lack of insight has been largely demonstrated in schizophrenia, other psychoses and bipolar disorder [64–67]. DSM-5 included an "insight" specifier in OCD, body dysmorphic and hoarding disorder. Also, different levels of lack of insight, from good to absent, have been found in other psychiatric disorders, like depressive and anxiety disorders, specific and social phobias, Alzheimer disease and other neuro-

Patients with anorexia nervosa (AN) commonly lack insight, at least in the early stages of illness. This element will determine important difficulties in assessment, lack of compliance or avoidance of treatment, frequent relapses and also may limit the identification of eating disorders. These patients have distorted cognitions about body weight and shape and also, they are ambivalent regarding motivation to recover [72]. On the other hand, patients with bulimia nervosa (BN) have typically

Until now there is not a disorder-specific scale for the assessment of insight in patients with eating disorders. Many researchers use SAI-ED (the Schedule for the Assessment of Insight for EDs), a short self-report questionnaire, which has only seven items. Even if the SAI-ED has not been fully validated, has a significant level

In their study evaluating the clinical insight in 193 patients with anorexia nervosa, Gorwood et al. observed that 88% of patients (171) had a high level of insight (SAI-ED total score > 4) and 12% of patients (22) had a poor insight

1.Insight was not improved in a vast majority of patients, even if they followed 4 months of specialized care and all clinical and cognitive markers improved.

in binge eating disorders or other eating and feeding disorders [62].

**54**

(SAI-ED < 4).

Other studies revealed other factors correlated with insight (cognitive functions memory and executive functions), psychiatric and addictive comorbidities, associated personality disorders prescribed psychotropic drugs, social cognitions, use of psychotherapy [72–76].

#### **11. Psychiatric comorbidities in eating disorders**

Beside comorbid somatic conditions of eating disorders (anemia, arteriosclerosis, hypertension, high cholesterol, high triglycerides, myocardial infarction, lung problems, stomach ulcer, Bowel problems, liver diseases, fibromyalgia, stroke, epilepsy or seizures, cancer, arthritis, osteoporosis, sleep problems), all three EDs (eating disorders) are associated with other psychiatric conditions, especially mood disorders, anxiety disorders, posttraumatic stress disorder, substance use disorder and personality or conduct disorder [77].

Regarding mood disorders, most common associated with EDs are major depressive disorder, persistent depression, bipolar I [78]. Affective disorders, substance use disorders and anxiety disorders represent the most common predictive factors for suicide. Researchers have reported also that eating disorders are associated with suicide. The meta-analysis of Smith et al. [78], which included 2611 longitudinal studies, concluded that ED diagnosis is significantly associated with an increased risk for suicide attempt (SA) although the rate of SA varied considerably across studies [78]. In the group of patients with anorexia nervosa (AN), the rate of SA was between 3 and 20% [79]; in bulimia nervosa patients (BN), the rate ranged between 25 and 35% [79]; and in BED patients, the rate was 12.5% [78] and 20.8% when combining all EDs [80]. In the study of Udo et al., which included 36,171 respondents in the Third National Epidemiological Survey on Alcohol and Related Conditions (NESARC-III), the prevalence of suicide attempts was 24.8% for AN, 15.5% for anorexia nervosa-restricted type (AN-R), 44.1% for anorexia nervosa binge/purge type (AN-BP), 31.4% for bulimia nervosa, and 22.9% for binge-eating disorder (BID) [77].

Regarding anxiety disorders, most common associated with eating disorders are panic disorder, social anxiety disorder, specific phobias and general anxiety disorder [78]. The association between social anxiety and EDs could be a part of a wider socio-emotional phenotype which it is considered to contribute to the development and maintenance of EDs. SA may be a risk factor for ED, or SA may be secondary to the ED, as a consequence of ED psychopathology or malnutrition [81].

Abuse of substances is common in EDs, the lifetime prevalence being estimated between 23 and 37% [82]. Tobacco, caffeine and alcohol were the most prevalent SUD in the study of Bahji et al., being followed by cannabis and cocaine [83, 84].

Between axis II DSM diagnoses, most common comorbidities in ED are antisocial, borderline and schizotypal personality disorders and conduct disorders [78].

#### **Conflict of interest**

The authors declare that they have no conflict of interest.

*Neurological and Mental Disorders*

### **Author details**

Bianca Suciu\* and Cătălina-Angela Crișan Department of Neuroscience, Discipline of Psychiatry and Pediatric Psychiatry, Iuliu Haţieganu University of Medicine and Pharmacy Cluj-Napoca, Romania

\*Address all correspondence to<EMAIL_ADDRESS>
© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**57**

*Feeding and Eating Disorders*

**References**

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

[1] Hay P. Current approach to eating disorders: A clinical update. Internal Medicine Journal. 2020;**50**(1):24-29

of caring for someone with anorexia nervosa: Qualitative study. The British Journal of Psychiatry.

[10] Stice E, Marti C, Durant S. Risk factors for onset of eating disorders: Evidence of multiple risk pathways from an 8-year prospective study. Behaviour Research and Therapy.

[11] Arcelus J, Witcomb G, Mitchell A. Prevalence of eating disorders amongst dancers: A systemic review and metaanalysis. European Eating Disorders

[12] Arcelus J. Mortality rates in patients with anorexia nervosa and other eating disorders. Archives of General

2005;**187**(5):444-449

2011;**49**(10):622-627

Review. 2013;**22**(2):92-101

Psychiatry. 2011;**68**(7):724

2011

[13] Smith J. The Parent' s Guide to Eating Disorders. Oxford: Lion Hutton;

[14] Davis C, Katzman D, Kaptein S, Kirsh C, Brewer H, Kalmbach K, et al. The prevalence of high-level exercise in the eating disorders: Etiological implications. Comprehensive Psychiatry. 1997;**38**(6):321-326

[15] Beumont P, Arthur B, Russell J, Touyz S. Excessive physical activity in dieting disorder patients: Proposals for a supervised exercise program. The International Journal of Eating

[16] Davis C, Kennedy S, Ravelski E, Dionne M. The role of physical activity in the development and maintenance of eating disorders. Psychological Medicine. 1994;**24**(4):957-967

[17] Touyz SW, Beumont PJV, Hook S. Exercise anorexia: A new dimension in anorexia nervosa. In: Handbook of

Disorders. 1994;**15**(1):21-36

Lambert G, Tavolacci MP. Prevalence of eating disorders over the 2000-2018 period: A systematic literature review. The American Journal of Clinical Nutrition. 2019;**109**:1402-1413

[2] Galmiche M, Déchelotte P,

[3] Hudson J, Hiripi E, Pope H, Kessler R. The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication. Biological Psychiatry.

[4] Hay P, Mitchison D, Lopez Collado AE, González-Chica DA, Stocks N, Touyz S. Burden and health-related quality of life of eating disorders, including avoidant/restrictive food intake disorder (ARFID), in the Australian population. Journal of Eating

[5] Udo T, Grilo CM. Prevalence and correlates of DSM-5–defined eating disorders in a nationally representative

[6] Smink FR, Van Hoeken D, Hoek HW. Epidemiology of eating disorders: Incidence, prevalence and mortality rates. Current Psychiatry Reports.

sample of US adults. Biological Psychiatry. 2018;**84**:345-354

[7] Mulders-Jones B, Mitchison D, Girosi F, Hay P. Socioeconomic correlates of eating disorder symptoms in an Australian population-based sample.

[8] Collier D, Treasure J. The aetiology of eating disorders. The British Journal of Psychiatry. 2004;**185**(5):363-365

[9] Whitney J, Murray J, Gavan K, Todd G, Whitaker W, Treasure J. Experience

PLoS One. 2017;**12**:e0170603

2007;**61**(3):348-358

Disorders. 2017;**5**:21

2012;**14**:406-414

### **References**

*Neurological and Mental Disorders*

**56**

**Author details**

Bianca Suciu\* and Cătălina-Angela Crișan

provided the original work is properly cited.

\*Address all correspondence to<EMAIL_ADDRESS>
Department of Neuroscience, Discipline of Psychiatry and Pediatric Psychiatry, Iuliu Haţieganu University of Medicine and Pharmacy Cluj-Napoca, Romania

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

[1] Hay P. Current approach to eating disorders: A clinical update. Internal Medicine Journal. 2020;**50**(1):24-29

[2] Galmiche M, Déchelotte P, Lambert G, Tavolacci MP. Prevalence of eating disorders over the 2000-2018 period: A systematic literature review. The American Journal of Clinical Nutrition. 2019;**109**:1402-1413

[3] Hudson J, Hiripi E, Pope H, Kessler R. The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication. Biological Psychiatry. 2007;**61**(3):348-358

[4] Hay P, Mitchison D, Lopez Collado AE, González-Chica DA, Stocks N, Touyz S. Burden and health-related quality of life of eating disorders, including avoidant/restrictive food intake disorder (ARFID), in the Australian population. Journal of Eating Disorders. 2017;**5**:21

[5] Udo T, Grilo CM. Prevalence and correlates of DSM-5–defined eating disorders in a nationally representative sample of US adults. Biological Psychiatry. 2018;**84**:345-354

[6] Smink FR, Van Hoeken D, Hoek HW. Epidemiology of eating disorders: Incidence, prevalence and mortality rates. Current Psychiatry Reports. 2012;**14**:406-414

[7] Mulders-Jones B, Mitchison D, Girosi F, Hay P. Socioeconomic correlates of eating disorder symptoms in an Australian population-based sample. PLoS One. 2017;**12**:e0170603

[8] Collier D, Treasure J. The aetiology of eating disorders. The British Journal of Psychiatry. 2004;**185**(5):363-365

[9] Whitney J, Murray J, Gavan K, Todd G, Whitaker W, Treasure J. Experience

of caring for someone with anorexia nervosa: Qualitative study. The British Journal of Psychiatry. 2005;**187**(5):444-449

[10] Stice E, Marti C, Durant S. Risk factors for onset of eating disorders: Evidence of multiple risk pathways from an 8-year prospective study. Behaviour Research and Therapy. 2011;**49**(10):622-627

[11] Arcelus J, Witcomb G, Mitchell A. Prevalence of eating disorders amongst dancers: A systemic review and metaanalysis. European Eating Disorders Review. 2013;**22**(2):92-101

[12] Arcelus J. Mortality rates in patients with anorexia nervosa and other eating disorders. Archives of General Psychiatry. 2011;**68**(7):724

[13] Smith J. The Parent' s Guide to Eating Disorders. Oxford: Lion Hutton; 2011

[14] Davis C, Katzman D, Kaptein S, Kirsh C, Brewer H, Kalmbach K, et al. The prevalence of high-level exercise in the eating disorders: Etiological implications. Comprehensive Psychiatry. 1997;**38**(6):321-326

[15] Beumont P, Arthur B, Russell J, Touyz S. Excessive physical activity in dieting disorder patients: Proposals for a supervised exercise program. The International Journal of Eating Disorders. 1994;**15**(1):21-36

[16] Davis C, Kennedy S, Ravelski E, Dionne M. The role of physical activity in the development and maintenance of eating disorders. Psychological Medicine. 1994;**24**(4):957-967

[17] Touyz SW, Beumont PJV, Hook S. Exercise anorexia: A new dimension in anorexia nervosa. In: Handbook of

Eating Disorders: Part 1. Amsterdam: Elsevier; 1987. pp. 143-157

[18] Epling WF, Pierce WD. Activity Anorexia: Theory, Research and Treatment. Lawarence Erlbaum Associates: Mahwan NJ; 1996

[19] Ackard D, Brehm B, Steffen J. Exercise and eating disorders in collegeaged women: Profiling excessive exercisers. Eating Disorders. 2002;**10**(1):31-47

[20] Steffen J, Brehm B. The dimensions of obligatory exercise. Eating Disorders. 1999;**7**(3):219-226

[21] Kron L, Katz J, Gorzynski G, Weiner H. Hyperactivity in anorexia nervosa: A fundamental clinical feature. Comprehensive Psychiatry. 1978;**19**(5):433-440

[22] Solenberger S. Exercise and eating disorders. Eating Behaviors. 2001;**2**(2):151-168

[23] Strober M, Freeman R, Morrell W. The long-term course of severe anorexia nervosa in adolescents: Survival analysis of recovery, relapse, and outcome predictors over 10-15 years in a prospective study. The International Journal of Eating Disorders. 1997;**22**(4):339-360

[24] Norris M, Harrison M, Isserlin L, Robinson A, Feder S, Sampson M. Gastrointestinal complications associated with anorexia nervosa: A systematic review. The International Journal of Eating Disorders. 2015;**49**(3):216-237

[25] Chami T, Nikoomanesh P, Katz P. An unusual presentation of pill-induced esophagitis. Gastrointestinal Endoscopy. 1995;**42**(3):263-265

[26] Miller K. Medical findings in outpatients with anorexia nervosa. Archives of Internal Medicine. 2005;**165**(5):561

[27] Douglas G, Nicol F, Robertson C. Macleod's Clinical Examination. 13th ed. Edinburgh: Churchill Livingstone Elsevier; 2013

[28] Stratton R, Dixon R, Longmore D, Stroud M, Elia M. Effect of recalled weight and height on malnutrition risk. Clinical Nutrition. 2003;**22**:S9-S10

[29] Sachs K, Harnke B, Mehler P, Krantz M. Cardiovascular complications of anorexia nervosa: A systematic review. The International Journal of Eating Disorders. 2015;**49**(3):238-248

[30] Weed LL. Medical Records that Guide and Teach. The New England Journal of Medicine. 1968;278(11):593- 600. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (5th ed.) (DSM-5). Washington DC: American Psychiatric Association; 2013

[31] World Health Organization. International Statistical Classification of Diseases and Related Health Problems, 11th Revision ICD-11. Geneva: World Health Organization; 2019

[32] International Advisory Group for the Revision of ICD-10 Mental Behavioural Disorders. A conceptual framework for the revision of the ICD-10 classification of mental and behavioural disorders. World Psychiatry. 2011;**10**(2):86-92. DOI: 10.1002/j.2051-5545.2011.tb00022.x

[33] Keeley JW, Reed GM, Roberts MC, Evans SC, Medina-Mora ME, Robles R. Developing a science of clinical utility in diagnostic classification systems: Field study strategies for ICD-11 mental and behavioral disorders. American Psychologist Journal. 2016;**71**(1):3. DOI: 10.1037/a0039972

**59**

*Feeding and Eating Disorders*

disorders. World Psychiatry. 2015;**14**(1):82-90. DOI: 10.1002/

[36] Attia E, Becker AE, Bryant-Waugh R, Hoek HW, Kreipe RE, Marcus MD. Feeding and eating disorders in DSM-5. The American Journal of Psychiatry. 2013;**170**(11):1237-1239. DOI: 10.1176/

appi.ajp.2013.13030326

[37] Al-Adawi S, Bax B, Bryant-Waugh R, Claudino AM, Hay P, Monteleone P. Revision of ICD status

update on feeding and eating disorders. Advances in Eating Disorders. 2013;**1**(1):10-20. DOI: 10.1080/21662630.2013.742971

10.1542/peds.2011-3663

DOI: 10.1002/erv.2297

[38] Field AE, Sonneville KR, Micali N, Crosby RD, Swanson SA, Laird NM, et al. Prospective association of common eating disorders and adverse outcomes. Pediatrics. 2012;**130**(2):e289-e295. DOI:

[39] Fitzsimmons-Craft EE, Ciao AC, Accurso EC, Pisetsky EM, Peterson CB, Byrne CE. Subjective and objective binge eating in relation to eating disorder symptomatology, depressive symptoms, and self-esteem among treatment-seeking adolescents with bulimia nervosa. European Eating Disorders Review. 2014;**22**(4):230-236.

[40] Watson HJ, Fursland A, Bulik CM, Nathan P. Subjective binge eating with compensatory behaviors: A variant presentation of bulimia nervosa.

wps.20189

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

The International Journal of Eating Disorders. 2013;**46**(2):119-126. DOI:

[41] Salvioli B, Pellicciari A, Iero L, Di Pietro E, Moscano F, Gualandi S, et al. Audit of digestive complaints and psychopathological traits in patients with eating disorders: A prospective study. Digestive and Liver Disease.

[42] Aziz Q, Fass R, Gyawali C, Miwa H, Pandolfino J, Zerbib F. Esophageal disorders. Gastroenterology. 2016;**150**(6):1368-1379

[43] Lacy B, Mearin F, Chang L, Chey W, Lembo A, Simren M, et al. Bowel disorders. Gastroenterology.

2016;**150**(6):1393.e5-1407.e5

[44] Hay P, Chinn D, Forbes D,

[45] National Institute for Health and Care Excellence (NICE). Eating disorders: Recognition and Treatment Full Guideline. 2017. Available from: https://www.nice. org.uk/guidance/ng69/evidence/ full-guideline-pdf-161214767896

[46] Hilbert A, Hoek HW, Schmidt R. Evidence-based clinical guidelines foreating disorders: International comparison. Current Opinion in Psychiatry. 2017;**30**:423-437

[47] Hay PJ, Touyz S, Claudino AM, Lujic S, Smith CA, Madden S. Inpatient

versusoutpatient care, partial hospitalization and waiting list for people with eating disorders. Cochrane Database of Systematic Reviews. 2019:CD010827. DOI: 10.1002/14651858.

CD010827.pub2

Madden S, Newton R, Sugenor L. Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of eating disorders. The Australian and New Zealand Journal of Psychiatry. 2014;**48**:977-1008

10.1002/eat.22052

2013;**45**(8):639-644

[34] First MB, Reed GM, Hyman SE, Saxena S. The development of the ICD-11 clinical descriptions and diagnostic guidelines for mental and behavioural

[35] Uher R, Rutter M. Classification of feeding and eating disorders: Review of evidence and proposals for ICD-11. World Psychiatry. 2012;**11**(2):80-92. DOI: 10.1016/j.wpsyc.2012.05.005

#### *Feeding and Eating Disorders DOI: http://dx.doi.org/10.5772/intechopen.92218*

*Neurological and Mental Disorders*

Elsevier; 1987. pp. 143-157

Eating Disorders: Part 1. Amsterdam:

Archives of Internal Medicine.

[27] Douglas G, Nicol F, Robertson C. Macleod's Clinical Examination. 13th ed. Edinburgh: Churchill Livingstone

[28] Stratton R, Dixon R, Longmore D, Stroud M, Elia M. Effect of recalled weight and height on malnutrition risk. Clinical Nutrition. 2003;**22**:S9-S10

[29] Sachs K, Harnke B, Mehler P,

[30] Weed LL. Medical Records that Guide and Teach. The New England Journal of Medicine. 1968;278(11):593- 600. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders (5th ed.) (DSM-5). Washington DC: American Psychiatric

[31] World Health Organization.

[32] International Advisory Group for the Revision of ICD-10 Mental Behavioural Disorders. A conceptual framework for the revision of the ICD-10 classification of mental and behavioural disorders. World Psychiatry. 2011;**10**(2):86-92. DOI: 10.1002/j.2051-5545.2011.tb00022.x

[33] Keeley JW, Reed GM, Roberts MC,

Psychologist Journal. 2016;**71**(1):3. DOI:

Evans SC, Medina-Mora ME, Robles R. Developing a science of clinical utility in diagnostic classification systems: Field study strategies for ICD-11 mental and behavioral disorders. American

10.1037/a0039972

Health Organization; 2019

International Statistical Classification of Diseases and Related Health Problems, 11th Revision ICD-11. Geneva: World

Krantz M. Cardiovascular complications of anorexia nervosa: A systematic review. The International Journal of Eating Disorders. 2015;**49**(3):238-248

2005;**165**(5):561

Elsevier; 2013

Association; 2013

[18] Epling WF, Pierce WD. Activity Anorexia: Theory, Research and Treatment. Lawarence Erlbaum Associates: Mahwan NJ; 1996

[19] Ackard D, Brehm B, Steffen J. Exercise and eating disorders in collegeaged women: Profiling excessive exercisers. Eating Disorders.

[20] Steffen J, Brehm B. The dimensions of obligatory exercise. Eating Disorders.

[21] Kron L, Katz J, Gorzynski G, Weiner H. Hyperactivity in anorexia nervosa: A fundamental clinical feature. Comprehensive Psychiatry.

[22] Solenberger S. Exercise and eating disorders. Eating Behaviors.

nervosa in adolescents: Survival analysis of recovery, relapse, and outcome predictors over 10-15 years in a prospective study. The International

Journal of Eating Disorders.

[24] Norris M, Harrison M, Isserlin L, Robinson A, Feder S, Sampson M. Gastrointestinal

1997;**22**(4):339-360

1995;**42**(3):263-265

[23] Strober M, Freeman R, Morrell W. The long-term course of severe anorexia

complications associated with anorexia nervosa: A systematic review. The International Journal of Eating Disorders. 2015;**49**(3):216-237

[25] Chami T, Nikoomanesh P, Katz P. An unusual presentation of pill-induced esophagitis. Gastrointestinal Endoscopy.

[26] Miller K. Medical findings in outpatients with anorexia nervosa.

2002;**10**(1):31-47

1999;**7**(3):219-226

1978;**19**(5):433-440

2001;**2**(2):151-168

**58**

[34] First MB, Reed GM, Hyman SE, Saxena S. The development of the ICD-11 clinical descriptions and diagnostic guidelines for mental and behavioural disorders. World Psychiatry. 2015;**14**(1):82-90. DOI: 10.1002/ wps.20189

[35] Uher R, Rutter M. Classification of feeding and eating disorders: Review of evidence and proposals for ICD-11. World Psychiatry. 2012;**11**(2):80-92. DOI: 10.1016/j.wpsyc.2012.05.005

[36] Attia E, Becker AE, Bryant-Waugh R, Hoek HW, Kreipe RE, Marcus MD. Feeding and eating disorders in DSM-5. The American Journal of Psychiatry. 2013;**170**(11):1237-1239. DOI: 10.1176/ appi.ajp.2013.13030326

[37] Al-Adawi S, Bax B, Bryant-Waugh R, Claudino AM, Hay P, Monteleone P. Revision of ICD status update on feeding and eating disorders. Advances in Eating Disorders. 2013;**1**(1):10-20. DOI: 10.1080/21662630.2013.742971

[38] Field AE, Sonneville KR, Micali N, Crosby RD, Swanson SA, Laird NM, et al. Prospective association of common eating disorders and adverse outcomes. Pediatrics. 2012;**130**(2):e289-e295. DOI: 10.1542/peds.2011-3663

[39] Fitzsimmons-Craft EE, Ciao AC, Accurso EC, Pisetsky EM, Peterson CB, Byrne CE. Subjective and objective binge eating in relation to eating disorder symptomatology, depressive symptoms, and self-esteem among treatment-seeking adolescents with bulimia nervosa. European Eating Disorders Review. 2014;**22**(4):230-236. DOI: 10.1002/erv.2297

[40] Watson HJ, Fursland A, Bulik CM, Nathan P. Subjective binge eating with compensatory behaviors: A variant presentation of bulimia nervosa.

The International Journal of Eating Disorders. 2013;**46**(2):119-126. DOI: 10.1002/eat.22052

[41] Salvioli B, Pellicciari A, Iero L, Di Pietro E, Moscano F, Gualandi S, et al. Audit of digestive complaints and psychopathological traits in patients with eating disorders: A prospective study. Digestive and Liver Disease. 2013;**45**(8):639-644

[42] Aziz Q, Fass R, Gyawali C, Miwa H, Pandolfino J, Zerbib F. Esophageal disorders. Gastroenterology. 2016;**150**(6):1368-1379

[43] Lacy B, Mearin F, Chang L, Chey W, Lembo A, Simren M, et al. Bowel disorders. Gastroenterology. 2016;**150**(6):1393.e5-1407.e5

[44] Hay P, Chinn D, Forbes D, Madden S, Newton R, Sugenor L. Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the treatment of eating disorders. The Australian and New Zealand Journal of Psychiatry. 2014;**48**:977-1008

[45] National Institute for Health and Care Excellence (NICE). Eating disorders: Recognition and Treatment Full Guideline. 2017. Available from: https://www.nice. org.uk/guidance/ng69/evidence/ full-guideline-pdf-161214767896

[46] Hilbert A, Hoek HW, Schmidt R. Evidence-based clinical guidelines foreating disorders: International comparison. Current Opinion in Psychiatry. 2017;**30**:423-437

[47] Hay PJ, Touyz S, Claudino AM, Lujic S, Smith CA, Madden S. Inpatient versusoutpatient care, partial hospitalization and waiting list for people with eating disorders. Cochrane Database of Systematic Reviews. 2019:CD010827. DOI: 10.1002/14651858. CD010827.pub2

[48] Long C. Assessment and management of eating disordered patients who over-exercise: A fouryear follow-up of six single case studies. Journal of Mental Health. 1995;**4**(3):309-316

[49] Thien V, Thomas A, Markin D, Birmingham C. Pilot study of a graded exercise program for the treatment of anorexia nervosa. The International Journal of Eating Disorders. 2000;**28**(1):101-106

[50] Saudek C, Felig P. The metabolic events of starvation. The American Journal of Medicine. 1976;**60**(1):117-126

[51] Boateng A, Sriram K, Meguid M, Crook M. Refeeding syndrome: Treatment considerations based on collective analysis of literature case reports. Nutrition. 2010;**26**(2):156-167

[52] Keys A. The biology of human starvation. The American Journal of Clinical Nutrition. 1978;**31**(2):197-197

[53] Madden S, Miskovic-Wheatley J, Clarke S, Touyz S, Hay P, Kohn MR. Outcomes of a rapid refeeding protocol in adolescent anorexia nervosa. Journal of Eating Disorders. 2015;**3**:8

[54] Schorr M, Klibanski A. Anorexia nervosa and bone. Current Opinion Endocrine and Metabolic Research. 2018;**3**:74-82

[55] Treasure J, Cardi V, Leppanen J, Turton R. New treatment approaches for severe and enduring eating disorders. Physiology & Behavior. 2015;**152**:456-465

[56] Zipfel S, Giel K, Bulik C, Hay P, Schmidt U. Anorexia nervosa: Aetiology, assessment, and treatment. The Lancet Psychiatry. 2015;**2**(12):1099-1111

[57] Dalle Grave R, Calugi S, Sartirana M, Fairburn CG.

Transdiagnostic cognitive behaviour therapy for adolescents with an eating disorder who are not underweight. Behaviour Ressearch and Therapy. 2015;**73**:79-82

[58] Schmidt U, Startup H, Treasure J. A Cognitive-Interpersonal Therapy Workbook for Treating Anorexia Nervosa: The Maudsley Model. Abingdon, UK: Routledge; 2018

[59] Attia E, Steinglass JE, Walsh BT, Wang Y, Wu P, Schreyer C. Olanzapine versus placebo in adult outpatients with anorexia nervosa: A randomized clinical trial. The American Journal of Psychiatry. 2019;**176**:449-456

[60] Hilbert A, Petroff D, Herpertz S, Pietrowsky R, Tuschen-Caffier B, Vocks S. Meta-analysis of the efficacy of psychological and medical treatments for binge-eating disorder. Journal of Consulting and Clinical Psychology. 2019;**87**:91-105

[61] Eddy KT, Tabri N, Thomas JJ, Murray HB, Keshaviah A, Hastings E. Recovery from anorexia nervosa and bulimia nervosa at 22-year followup. The Journal of Clinical Psychiatry. 2017;**78**:184-189

[62] Vall E, Wade TD. Predictors of treatment outcome in individuals with eating disorders: A systematic review and meta-analysis. The International Journal of Eating Disorders. 2015;**48**:946-971

[63] Marková IS. Insight in Psychiatry. Cambridge University Press; 2005

[64] David AS. Insight and psychosis. The British Journal of Psychiatry. 1990;**156**:798-808

[65] Amador XF, Strauss DH, Yale SA, Gorman JM. Awareness of illness in schizophrenia. Schizophrenia Bulletin. 1991;**17**:113-132

**61**

*Feeding and Eating Disorders*

Quarterly. 1993;**64**:305-318

2015;**37**(3):152-156

*DOI: http://dx.doi.org/10.5772/intechopen.92218*

[74] Nair A, Palmer EC, Aleman A, David AS. Relationship between cognition, clinical and cognitive insight in psychotic disorders: A review and meta-analysis. Schizophrenia Research.

[75] Steinglass JE, Eisen JL, Attia E, Mayer L, Walsh BT. Is anorexia nervosa a delusional disorder? An assessment of eating beliefs in anorexia nervosa. Journal of Psychiatric Practice.

[76] Yen CF, Hsiao RC, Chen CC, Lin HC, Yen CN, Ko CH, et al. The role of insight to alcohol use disorders

[77] Udo T, Grilo CM. Psychiatric and medical correlates of DSM-5 eating disoders in a nationally representative sample of adults in the United States. The International Journal of Eating

[79] Franko DL, Keel PK. Suicidality in eating disorders: Occurrence, correlates, and clinical implications. Clinical Psychology Review. 2006;**26**(6):769-782

[80] Carano A, De Berardis D, Campanella D, Serroni N, Ferri F, Di Lorio G, et al. Alexithymia and suicide ideation in a sample of patients with binge eating disorder. Journal of Psychiatric Practice. 2012;**18**(1):5-11

[81] Ahn J, Lee J, Jung Y. Predictors of suicide attempts in individuals with eating disorders. Suicide and Life-Threatening Behavior.

2018;**49**(3):789-797

in insight to schizophrenia. Comprehensive Psychiatry.

Disorders. 2019;**52**:42-50

2018;**49**(1):221-239

[78] Smith AR, Velkoff EA, Ribeiro JD, Franklin J. Are eating disorders and related symptoms risk factors for suicidal thoughts and behaviors? A meta-analysis. Suicide & Life-Threatening Behavior.

2014;**152**(1):191-200

2007;**13**(2):65-71

2009;**50**(1):58-62

[66] Amador XF, Strauss DH. Poor insight in schizophrenia. Psychiatric

[67] de Assis da Silva R, Mograbi DC, Camelo EVM, Bifano J, Wainstok M, Silveira LAS, et al. Insight in bipolar disorder: A comparison between mania, depression and euthymia using the insight scale for affective disorders. Trends in Psychiatry and Psychotherapy.

[68] Lee MS, Lee HY, Kang SG, Yang J, Ahn H, Rhee M. Variables influencing antidepressant medication adherence for treating outpatients with depressive

[69] Menzies RG, Harris LM, Jones MK. Evidence from three fearful samples for poor insight type specific phobia. Depression and Anxiety. 1998;**8**:29-32

[71] Konstantakopoulos G, Tchanturia K, Surguladze SA, David AS. Insight in eating disoders: Clinical and cognitive correlates. Psychological Medicine.

[72] Gorwood P, Duriez P, Lengvenyte A, Guillaume S. Criquillion, on behalf of the FFAB network. Clinical insight in anorexia nervosa: Associated and predictive factors. Psychiatry Research.

[73] Catapano F, Perris F, Fabrazzo M, Cioffi V, Giacco D, De Santis V, et al. Obssessive-compulsive disorder with poor-insight: a three-year prospective study. Progress in Neuropsychopharmacology and Biological Psychiatry. 2010;**34**(2):323-330

disorders. Journal of Affective Disorders. 2010;**123**:216-221

[70] Vigne P, de Menezes GB, Harrison BJ, Fontenelle LF. A study of poor insight in social anxiety disorders. Psychiatry Reaserch.

2014;**219**:556-561

2011;**41**:1951-1961

2019;**281**:112561

*Feeding and Eating Disorders DOI: http://dx.doi.org/10.5772/intechopen.92218*

[66] Amador XF, Strauss DH. Poor insight in schizophrenia. Psychiatric Quarterly. 1993;**64**:305-318

*Neurological and Mental Disorders*

[48] Long C. Assessment and management of eating disordered patients who over-exercise: A fouryear follow-up of six single case studies. Journal of Mental Health.

Transdiagnostic cognitive behaviour therapy for adolescents with an eating disorder who are not underweight. Behaviour Ressearch and Therapy.

[58] Schmidt U, Startup H, Treasure J. A Cognitive-Interpersonal Therapy Workbook for Treating Anorexia Nervosa: The Maudsley Model. Abingdon, UK: Routledge; 2018

[59] Attia E, Steinglass JE, Walsh BT, Wang Y, Wu P, Schreyer C. Olanzapine versus placebo in adult outpatients with anorexia nervosa: A randomized clinical trial. The American Journal of

[60] Hilbert A, Petroff D, Herpertz S, Pietrowsky R, Tuschen-Caffier B, Vocks S. Meta-analysis of the efficacy of psychological and medical treatments for binge-eating disorder. Journal of Consulting and Clinical Psychology.

[61] Eddy KT, Tabri N, Thomas JJ,

Hastings E. Recovery from anorexia nervosa and bulimia nervosa at 22-year followup. The Journal of Clinical Psychiatry. 2017;**78**:184-189

[62] Vall E, Wade TD. Predictors of treatment outcome in individuals with eating disorders: A systematic review and meta-analysis. The International

[63] Marková IS. Insight in Psychiatry. Cambridge University Press; 2005

[64] David AS. Insight and psychosis. The British Journal of Psychiatry.

[65] Amador XF, Strauss DH, Yale SA, Gorman JM. Awareness of illness in schizophrenia. Schizophrenia Bulletin.

Journal of Eating Disorders.

2015;**48**:946-971

1990;**156**:798-808

1991;**17**:113-132

Murray HB, Keshaviah A,

Psychiatry. 2019;**176**:449-456

2019;**87**:91-105

2015;**73**:79-82

[49] Thien V, Thomas A, Markin D, Birmingham C. Pilot study of a graded exercise program for the treatment of anorexia nervosa. The International

[50] Saudek C, Felig P. The metabolic events of starvation. The American Journal of Medicine. 1976;**60**(1):117-126

[52] Keys A. The biology of human starvation. The American Journal of Clinical Nutrition. 1978;**31**(2):197-197

[53] Madden S, Miskovic-Wheatley J, Clarke S, Touyz S, Hay P, Kohn MR. Outcomes of a rapid refeeding protocol in adolescent anorexia nervosa. Journal

[54] Schorr M, Klibanski A. Anorexia nervosa and bone. Current Opinion Endocrine and Metabolic Research.

[55] Treasure J, Cardi V, Leppanen J, Turton R. New treatment approaches for severe and enduring eating disorders. Physiology & Behavior.

[56] Zipfel S, Giel K, Bulik C, Hay P, Schmidt U. Anorexia nervosa: Aetiology, assessment, and treatment. The Lancet Psychiatry. 2015;**2**(12):1099-1111

[57] Dalle Grave R, Calugi S, Sartirana M, Fairburn CG.

of Eating Disorders. 2015;**3**:8

2018;**3**:74-82

2015;**152**:456-465

Journal of Eating Disorders.

[51] Boateng A, Sriram K, Meguid M, Crook M. Refeeding syndrome: Treatment considerations based on collective analysis of literature case reports. Nutrition.

2010;**26**(2):156-167

1995;**4**(3):309-316

2000;**28**(1):101-106

**60**

[67] de Assis da Silva R, Mograbi DC, Camelo EVM, Bifano J, Wainstok M, Silveira LAS, et al. Insight in bipolar disorder: A comparison between mania, depression and euthymia using the insight scale for affective disorders. Trends in Psychiatry and Psychotherapy. 2015;**37**(3):152-156

[68] Lee MS, Lee HY, Kang SG, Yang J, Ahn H, Rhee M. Variables influencing antidepressant medication adherence for treating outpatients with depressive disorders. Journal of Affective Disorders. 2010;**123**:216-221

[69] Menzies RG, Harris LM, Jones MK. Evidence from three fearful samples for poor insight type specific phobia. Depression and Anxiety. 1998;**8**:29-32

[70] Vigne P, de Menezes GB, Harrison BJ, Fontenelle LF. A study of poor insight in social anxiety disorders. Psychiatry Reaserch. 2014;**219**:556-561

[71] Konstantakopoulos G, Tchanturia K, Surguladze SA, David AS. Insight in eating disoders: Clinical and cognitive correlates. Psychological Medicine. 2011;**41**:1951-1961

[72] Gorwood P, Duriez P, Lengvenyte A, Guillaume S. Criquillion, on behalf of the FFAB network. Clinical insight in anorexia nervosa: Associated and predictive factors. Psychiatry Research. 2019;**281**:112561

[73] Catapano F, Perris F, Fabrazzo M, Cioffi V, Giacco D, De Santis V, et al. Obssessive-compulsive disorder with poor-insight: a three-year prospective study. Progress in Neuropsychopharmacology and Biological Psychiatry. 2010;**34**(2):323-330

[74] Nair A, Palmer EC, Aleman A, David AS. Relationship between cognition, clinical and cognitive insight in psychotic disorders: A review and meta-analysis. Schizophrenia Research. 2014;**152**(1):191-200

[75] Steinglass JE, Eisen JL, Attia E, Mayer L, Walsh BT. Is anorexia nervosa a delusional disorder? An assessment of eating beliefs in anorexia nervosa. Journal of Psychiatric Practice. 2007;**13**(2):65-71

[76] Yen CF, Hsiao RC, Chen CC, Lin HC, Yen CN, Ko CH, et al. The role of insight to alcohol use disorders in insight to schizophrenia. Comprehensive Psychiatry. 2009;**50**(1):58-62

[77] Udo T, Grilo CM. Psychiatric and medical correlates of DSM-5 eating disoders in a nationally representative sample of adults in the United States. The International Journal of Eating Disorders. 2019;**52**:42-50

[78] Smith AR, Velkoff EA, Ribeiro JD, Franklin J. Are eating disorders and related symptoms risk factors for suicidal thoughts and behaviors? A meta-analysis. Suicide & Life-Threatening Behavior. 2018;**49**(1):221-239

[79] Franko DL, Keel PK. Suicidality in eating disorders: Occurrence, correlates, and clinical implications. Clinical Psychology Review. 2006;**26**(6):769-782

[80] Carano A, De Berardis D, Campanella D, Serroni N, Ferri F, Di Lorio G, et al. Alexithymia and suicide ideation in a sample of patients with binge eating disorder. Journal of Psychiatric Practice. 2012;**18**(1):5-11

[81] Ahn J, Lee J, Jung Y. Predictors of suicide attempts in individuals with eating disorders. Suicide and Life-Threatening Behavior. 2018;**49**(3):789-797

[82] Treasure J, Schmidt U. The cognitive-interpersonal maintenance model of anorexia nervosa revisited: A summary of the evidence for cognitive, socio-emotional and interpersonal predisposing and perpetuating factors. Journal of Eating Disorders. 2013;**1**:13

[83] Hudson JI, Hiripi E, Pope HG, Kessler RC. The prevalence and correlates of eating disorders in the national comorbidity survey replication. Biological Psychiatry. 2007;**61**(3):348-358

[84] Bahji A, Mazhar MN, Hudson CC, Nadkarni P, MacNeil BA, Hawken E. Prevalence of substance use disorder comorbidity among individuals with eating disorders: A systematic review and meta-analysis. Psychiatry Reaserch. 2019;**273**:58-66

**63**

Section 2

Medical Aspects


**6. Conclusion**

Noble gases bind to proteins essentially through non-covalent van der Waals interactions, their binding constant depending on their electronic polarizability. In the three studied enzymes, gas occupancies were in the order of their polarizability, Xe > Kr > Ar, as it was already found for T4 lysozyme (Quillin et al., 2000). The only slight exception was the internal cavity of egg white lysozyme, where its smaller size prevented xenon higher occupancy.

The major physiological targets of gaseous anesthetics are postulated to be neuronal channels receptors, like the NMDA receptor which is inhibited by xenon (Campagna et al., 2003; Franks, 2008), or the GABAA receptor which could be modulated by argon (Abraini et al., 2003). However, at lower concentration, gas would bind mainly to globular targets, amongst them enzymes, whose functions would be modulated by the presence of inert gas.

From the present study, we can infer different mode of inhibition by gas. In urate oxidase, gas inhibited the catalytic reaction through an indirect mechanism; the presence of the gas within the cavity would prevent the cavity contraction, thus modifying the active site flexibility. In elastase, gas inhibited the catalytic reaction through a direct mechanism; the presence of the gas in the active site would prevent the substrate binding. In lysozyme, gas would not inhibit the catalytic reaction, their occupation being too weak.

Protein activity requires some conformational flexibility (Frauenfelder et al., 1991). In enzymes, the balance between conformational flexibility and rigidity is adjusted to optimize the catalytic efficiency for a given condition (Chiuri et al., 2009). Cavities would facilitate conformational changes and are though to play a key role in protein function (Hubbard et al., 1994). Anesthetics have been postulated to act by stabilizing high-energy conformers inducing altered functions (Eckenhoff, 2001; Johansson et al., 2005). High pressure was also postulated to stabilize high-energy conformers with altered functions (Frauenfelder et al., 1990; Akasaka, 2006; Fourme et al., 2006). Urate oxidase is thus a key example which highlights the effect of anesthetic, since this enzyme is both inhibited by gas presence in a hydrophobic cavity (Marassio et al., 2011) and by high pressure (Girard et al., 2010).

Inert gas binds to proteins through very weak non-covalent van der waals interaction. How such weak interactions could generate such high biological effect such as anesthesia ? It was suggested that anesthesia would arise from small effects at many biological targets (Eckenhoff, 2001). The present study would confirm this hypothesis, showing that some enzymes could be stabilized by the presence of gas in hydrophobic cavity (as in urate oxidase), some enzymes could be directly inhibited by gas (as in elastase case), and some enzymes are not affected by gas (as in the case of lysozyme). The mechanisms of neuroprotection and anesthesia by inert gases are thus very complex processes with many biological targets whose function are modulated (inhibited or potentiated) by the presence of gas.