There is no single cause of eating disorders. Many people with eating disorders also have
body image disturbance and a comorbid
body dysmorphic disorder (BDD), leading them to an altered perception of their body. Studies have found that a high proportion of individuals diagnosed with body dysmorphic disorder also had some type of eating disorder, with 15% of individuals having either anorexia nervosa or bulimia nervosa. Also, the media are oftentimes blamed for the rise in the incidence of eating disorders due to the fact that media images of idealized slim physical shape of people such as models and celebrities motivate or even force people to attempt to achieve slimness themselves. The media are accused of distorting reality, in the sense that people portrayed in the media are either naturally thin and thus unrepresentative of normality or unnaturally thin by forcing their bodies to look like the ideal image by putting excessive pressure on themselves to look a certain way. While past findings have described eating disorders as primarily psychological, environmental, and sociocultural, further studies have uncovered evidence that there is a genetic component.
Genetics Numerous studies show a
genetic predisposition toward eating disorders. Twin studies have found a slight instances of genetic variance when considering the different criterion of both anorexia nervosa and bulimia nervosa as endophenotypes contributing to the disorders as a whole. Twin studies also show that at least a portion of the vulnerability to develop eating disorders can be inherited, and there is evidence to show that there is a genetic locus that shows susceptibility for developing anorexia nervosa. Other cases are due to external reasons or developmental problems. There are also other neurobiological factors at play tied to emotional reactivity and impulsivity that could lead to binging and purging behaviors.
Epigenetics mechanisms are means by which environmental effects alter gene expression via methods such as
DNA methylation; these are independent of and do not alter the underlying DNA sequence. They are heritable, but also may occur throughout the lifespan, and are potentially reversible. Dysregulation of
dopaminergic neurotransmission due to epigenetic mechanisms has been implicated in various eating disorders. Other candidate genes for epigenetic studies in eating disorders include
leptin,
pro-opiomelanocortin (POMC) and
brain-derived neurotrophic factor (BDNF). There has found to be a genetic correlation between anorexia nervosa and OCD, suggesting a strong etiology. First and second relatives of probands with OCD have a greater chance of developing anorexia nervosa as genetic relatedness increases. disorders in the Diagnostic and Statistical Manual of Mental Health Disorders (
DSM-IV) published by the
American Psychiatric Association. There are various other psychological issues that may factor into eating disorders, some fulfill the criteria for a separate Axis I
diagnosis or a personality disorder which is coded
Axis II and thus are considered
comorbid to the diagnosed eating disorder. Axis II disorders are subtyped into 3 "clusters": A, B and C. The
causality between personality disorders and eating disorders has yet to be fully established. Some people have a previous disorder which may increase their vulnerability to developing an eating disorder. Some develop them afterwards. The severity and type of eating disorder symptoms have been shown to affect comorbidity. There has been controversy over various editions of the DSM diagnostic criteria including the latest edition, DSM-5, published in 2013.
Cognitive attentional bias Attentional bias may have an effect on eating disorders. Attentional bias is the preferential attention toward certain types of information in the environment while simultaneously ignoring others. Individuals with eating disorders may develop disordered schemata which focus on body size and eating, and these schemata may bias judgements, thoughts, and behaviours in a manner that is self-destructive or maladaptive. Information contained within those schemata is thought to be given the highest level of importance and overvalued among other cognitive structures. People who have eating disorders tend to pay more attention to stimuli related to food. For people struggling to recover from an eating disorder or addiction, this tendency to pay attention to certain signals while discounting others can make recovery that much more difficult. Other studies have noted that individuals with eating disorders have significant attentional biases associated with eating and weight stimuli.
Personality traits There are various childhood
personality traits associated with the development of eating disorders, such as perfectionism and neuroticism. These personality traits are found to link eating disorders and OCD. Many personality traits have a genetic component and are highly heritable. Maladaptive levels of certain traits may be acquired as a result of anoxic or traumatic brain injury, neurodegenerative diseases such as
Parkinson's disease,
neurotoxicity such as lead exposure, bacterial infection such as
Lyme disease or parasitic infection such as
Toxoplasma gondii as well as hormonal influences. While studies are still continuing via the use of various imaging techniques such as
fMRI; these traits have been shown to originate in various regions of the brain such as the
amygdala and the
prefrontal cortex. Disorders in the prefrontal cortex and the executive functioning system have been shown to affect eating behavior.
Celiac disease People with
gastrointestinal disorders may be more risk of developing disordered eating practices than the general population, principally restrictive eating disturbances. An association of
anorexia nervosa with
celiac disease has been found. The role that gastrointestinal symptoms play in the development of eating disorders seems rather complex. Some authors report that unresolved symptoms prior to gastrointestinal disease diagnosis may create a food aversion in these persons, causing alterations to their eating patterns. Other authors report that greater symptoms throughout their diagnosis led to greater risk. It has been documented that some people with celiac disease,
irritable bowel syndrome or
inflammatory bowel disease who are not conscious about the importance of strictly following their diet, choose to consume their trigger foods to promote weight loss. On the other hand, individuals with good dietary management may develop anxiety, food aversion and eating disorders because of concerns around cross contamination of their foods.
Environmental influences Child maltreatment Child abuse which encompasses physical, psychological, and sexual abuse, as well as neglect, has been shown to approximately triple the risk of an eating disorder.
Social isolation Social isolation has been shown to have a deleterious effect on an individual's physical and emotional well-being. Those that are socially isolated have a higher mortality rate in general as compared to individuals that have established social relationships. This effect on mortality is markedly increased in those with pre-existing medical or psychiatric conditions, and has been especially noted in cases of
coronary heart disease. "The magnitude of risk associated with social isolation is comparable with that of
cigarette smoking and other major
biomedical and
psychosocial risk factors." (Brummett
et al.) Social isolation can be inherently stressful, depressing and anxiety-provoking. In an attempt to ameliorate these distressful feelings an individual may engage in emotional eating in which food serves as a source of comfort. The loneliness of social isolation and the inherent stressors thus associated have been implicated as triggering factors in binge eating as well. Waller, Kennerley and Ohanian (2007) argued that both bingeing–vomiting and restriction are emotion suppression strategies, but they are just utilized at different times. For example, restriction is used to pre-empt any emotion activation, while bingeing–vomiting is used after an emotion has been activated.
Parental influence Parental influence has been shown to be an intrinsic component in the development of eating behaviors of children. This influence is manifested and shaped by a variety of diverse factors such as familial genetic predisposition, dietary choices as dictated by cultural or ethnic preferences, the parents' own body shape, how they talk about their own body, and eating patterns, the degree of involvement and expectations of their children's eating behavior as well as the interpersonal relationship of parent and child.
Hilde Bruch, a pioneer in the field of studying eating disorders, asserts that anorexia nervosa often occurs in girls who are high achievers, obedient, and always trying to please their parents. Their parents have a tendency to be over-controlling and fail to encourage the expression of emotions, inhibiting daughters from accepting their own feelings and desires. Adolescent females in these overbearing families lack the ability to be independent from their families, yet realize the need to, often resulting in rebellion. Controlling their food intake may make them feel better, as it provides them with a sense of control. Negative parental body-talk, meaning when a parent comments on their own weight, shape or size, is strongly correlated with disordered eating in their children. Children whose parents engage in self-talk about their weight frequently are three times as likely to practice extreme weight control behaviors such as disordered eating, than children who do not overhear negative parental body-talk. Additionally, negative body-talk from mothers is explicitly correlated with disordered eating in adolescent girls.
Peer pressure In various studies such as one conducted by
The McKnight Investigators,
peer pressure was shown to be a significant contributor to body image concerns and attitudes toward eating among subjects in their teens and early twenties. Eleanor Mackey and co-author, Annette M. La Greca of the University of Miami, studied 236 teen girls from public high schools in southeast Florida. "Teen girls' concerns about their own weight, about how they appear to others and their perceptions that their peers want them to be thin are significantly related to weight-control behavior", says psychologist Eleanor Mackey of the Children's National Medical Center in Washington and lead author of the study. "Those are really important." According to one study, 40% of 9- and 10-year-old girls are already trying to lose weight. Such dieting is reported to be influenced by peer behavior, with many of those individuals on a diet reporting that their friends also were dieting. The number of friends dieting and the number of friends who pressured them to diet also played a significant role in their own choices. Elite athletes have a significantly higher rate in eating disorders. Female athletes in sports such as gymnastics, ballet, diving, etc. are found to be at the highest risk among all athletes. Women are more likely than men to acquire an eating disorder between the ages of 13 and 25. About 0–15% of those with bulimia and anorexia are men. Other psychological problems that could possibly create an eating disorder such as Anorexia Nervosa are depression, and low self-esteem. Depression is a state of mind where emotions are unstable causing a person's eating habits to change due to sadness and no interest of doing anything. According to PSYCOM "Studies show that a high percentage of people with an eating disorder will experience depression." Depression is a state of mind where people seem to refuge without being able to get out of it. A big factor of this can affect people with their eating and this can mostly affect teenagers. Teenagers are big candidates for Anorexia for the reason that during the teenage years, many things start changing and they start to think certain ways. According to Life Works an article about eating disorders "People of any age can be affected by pressure from their peers, the media and even their families but it is worse when you're a teenager at school."
Cultural pressure Western perspective There is a cultural emphasis on thinness which is especially pervasive in western society. A child's perception of external pressure to achieve the ideal body that is represented by the media predicts the child's body image dissatisfaction, body dysmorphic disorder and an eating disorder. "The cultural pressure on men and women to be 'perfect' is an important predisposing factor for the development of eating disorders". Further, when women of all races base their evaluation of their self upon what is considered the culturally ideal body, the incidence of eating disorders increases. Socioeconomic status (SES) has been viewed as a risk factor for eating disorders, presuming that possessing more resources allows for an individual to actively choose to diet and reduce body weight. Some studies have also shown a relationship between increasing body dissatisfaction with increasing SES. However, once high socioeconomic status has been achieved, this relationship weakens and, in some cases, no longer exists. The media plays a major role in the way in which people view themselves. Countless magazine ads and commercials depict thin celebrities. Society has taught people that being accepted by others is necessary at all costs. This has led to the belief that in order to fit in one must look a certain way. Televised beauty competitions such as the
Miss America Competition contribute to the idea of what it means to be beautiful because competitors are evaluated on the basis of their opinion. In addition to socioeconomic status being considered a cultural risk factor so is the world of sports. Athletes and eating disorders tend to go hand in hand, especially the sports where weight is a competitive factor. Gymnastics, horse back riding, wrestling, body building,
nordic skiing and dancing are just a few that fall into this category of weight dependent sports. Eating disorders among individuals that participate in competitive activities, especially women, often lead to having physical and biological changes related to their weight that often mimic prepubescent stages. Oftentimes as women's bodies change they lose their competitive edge which leads them to taking extreme measures to maintain their younger body shape. Men often struggle with binge eating followed by excessive exercise while focusing on building muscle rather than losing fat, but this goal of gaining muscle is just as much an eating disorder as obsessing over thinness. The following statistics taken from Susan Nolen-Hoeksema's book, (
ab)normal psychology, show the estimated percentage of athletes that struggle with eating disorders based on the category of sport. • Aesthetic sports (dance, figure skating, gymnastics) – 35% • Weight dependent sports (judo, wrestling) – 29% • Endurance sports (cycling, swimming, running) – 20% • Technical sports (golf, high jumping) – 14% • Ball game sports (volleyball, soccer) – 12% Although most of these athletes develop eating disorders to keep their competitive edge, others use exercise as a way to maintain their weight and figure. This is just as serious as regulating food intake for competition. Even though there is mixed evidence showing at what point athletes are challenged with eating disorders, studies show that regardless of competition level all athletes are at higher risk for developing eating disorders that non-athletes, especially those that participate in sports where thinness is a factor. Pressure from society is also seen within the homosexual community.
Gay men are at greater risk of eating disorder symptoms than heterosexual men. Within the gay culture, muscularity gives the advantages of both social and sexual desirability and also power. These pressures and ideas that another homosexual male may desire a mate who is thinner or muscular can possibly lead to eating disorders. The higher eating disorder symptom score reported, the more concern about how others perceive them and the more frequent and excessive exercise sessions occur. While there are many influences to how an individual processes their body image, the media does play a major role. Along with the media, parental influence, peer influence, and
self-efficacy beliefs also play a large role in an individual's view of themselves. The way the media presents images can have a lasting effect on an individual's perception of their body image. Eating disorders are a worldwide issue and while women are more likely to be affected by an eating disorder it still affects both genders (Schwitzer 2012). The media influences eating disorders whether shown in a positive or negative light, it then has a responsibility to use caution when promoting images that projects an ideal that many turn to eating disorders to attain. To try to address unhealthy body image in the fashion world, in 2015,
France passed a law requiring models to be declared healthy by a doctor to participate in fashion shows. It also requires re-touched images to be marked as such in magazines. There is a relationship between "thin ideal" social media content and body dissatisfaction and eating disorders among young adult women, especially in the Western hemisphere. New research points to an "internalization" of distorted images online, as well as negative comparisons among young adult women. Most studies have been based in the U.S., the U.K, and Australia, these are places where the thin ideal is strong among women, as well as the strive for the "perfect" body. as well as images promoting weight loss, tagged with the term "thinspiration". According to social comparison theory, young women have a tendency to compare their appearance to others, which can result in a negative view of their own bodies and altering of eating behaviors, that in turn can develop disordered eating behaviors. When body parts are isolated and displayed in the media as objects to be looked at, it is called objectification, and women are affected most by this phenomenon. Objectification increases self-objectification, where women judge their own body parts as a mean of praise and pleasure for others. There is a significant link between self-objectification, body dissatisfaction, and disordered eating, as the beauty ideal is altered through social media.
African perspective In the majority of many African communities, thinness is generally not seen as an ideal body type and most pressure to attain a slim figure may stem from influence or exposure to Western culture and ideology. Traditional African cultural ideals are reflected in the practice of some health professionals; in Ghana, pharmacists sell appetite stimulants to women who desire to, as Ghanaians stated, "grow fat". Girls are told that if they wish to find a partner and birth children they must gain weight. On the contrary, there are certain taboos surrounding a slim body image, specifically in West Africa. Lack of body fat is linked to poverty and
HIV/AIDS. However, the emergence of Western and European influence, specifically with the introduction of such fashion and modelling shows and competitions, is changing certain views among body acceptance, and the prevalence of eating disorders has consequently increased. Further, exposure to Western values through private Caucasian schools or caretakers is another possible factor related to acculturation which may be associated with the onset of eating disorders. Other factors which are cited to be related to the increasing prevalence of eating disorders in African communities can be related to sexual conflicts, such as psychosexual guilt, first sexual intercourse, and pregnancy. Traumatic events which are related to both family (i.e. parental separation) and eating related issues are also cited as possible effectors.
Asian perspective The West plays a role in Asia's economic development via foreign investments, advanced technologies joining financial markets, and the arrival of American and European companies in Asia, especially through outsourcing manufacturing operations. This exposure to Western culture, especially the media, imparts Western body ideals to Asian society, termed Westernization. Similarly to the West, researchers have identified the media as a primary source of pressures relating to physical appearance, which may even predict body change behaviors in males and females. Similar to studies conducted on Polynesian groups, ethnic Fijian traditional aesthetic ideals reflected a preference for a robust body shape; thus, the prevailing 'pressure to be slim,' thought to be associated with diet and disordered eating in many Western societies was absent in traditional Fiji. Additionally, traditional Fijian values would encourage a robust appetite and a widespread vigilance for and social response to weight loss. Individual efforts to reshape the body by dieting or exercise, thus traditionally was discouraged. However, studies conducted in 1995 and 1998 both demonstrated a link between the introduction of television in the country, and the emergence of eating disorders in young adolescent ethnic Fijian girls. Through the quantitative data collected in these studies there was found to be a significant increase in the prevalence of two key indicators of disordered eating: self-induced vomiting and high Eating Attitudes Test- 26. These results were recorded following prolonged television exposure in the community, and an associated increase in the percentage of households owning television sets. Additionally, qualitative data linked changing attitudes about dieting, weight loss and aesthetic ideas in the peer environment to Western media images. The impact of television was especially profound given the longstanding social and cultural traditions that had previously rejected the notions of dieting, purging and body dissatisfaction in Fiji.
Hong Kong From the early- to-mid- 1990s, a variant form of anorexia nervosa was identified in Hong Kong. This variant form did not share features of anorexia nervosa in the West, notably "fat-phobia" and distorted body image. However, it appears that rates of eating disorders in urban areas of India are increasing based on surveys from psychiatrists who were asked whether they perceived eating disorders to be a "serious clinical issue" in India. While on one hand there is increasing recognition of eating disorders in the country, there is also a persisting belief that this illness is alien to India. This prevents many sufferers from seeking professional help." 23.5% of respondents believed that rates of eating disorders were rising in Bangalore, 26.5% claimed that rates were stagnant, and 42%, the largest percentage, expressed uncertainty. It has been suggested that urbanization and socioeconomic status are associated with increased risk for body weight dissatisfaction. and African American women have reported the lowest levels of body dissatisfaction among the five major racial/ethnic groups in the US. However, recent research contradicts these findings, indicating that African American women may exhibit levels of body dissatisfaction comparable to other racial/ethnic minority groups. In this way, just because those who identify as African American may not internalize the thin ideal as strongly as other racial and ethnic groups, it does not mean that they do not hold other appearance ideals that may promote body shape concerns. Similarly, recent research shows that African Americans exhibit rates of disordered eating that are similar to or even higher than their white counterparts.
Native American Native American women are more likely than white women to both experience a fear of losing control over their eating and to abuse laxatives and diuretics for weight control purposes. They have comparable rates of binge eating and other disordered weight control behaviors in comparison to other racial groups. in direct contrast to food security, which is conceptualized as having access to sufficient, safe, and nutritious food to meet dietary needs and preferences. Notably, levels of food security exist on a continuum from reliable access to food to disrupted access to food. Multiple studies have found food insecurity to be associated with eating pathology. A study conducted on individuals visiting a food bank in Texas found higher food insecurity to be correlated with higher levels of binge eating, overall eating disorder pathology, dietary restraint, compensatory behaviors and weight self-stigma. Findings of a replication study with a larger, more diverse sample mirrored these results, and a study looking at the relationship between food insecurity and bulimia nervosa similarly found greater food insecurity to be associated with elevated levels of eating pathology.
Trauma One study has found that binge-eating disorder may stem from trauma, with some female patients engaging in these disorders to numb pain experienced through sexual trauma. There are various forms of trauma that individuals may have experienced, leading them to cope through an eating disorder. When in pain, individuals may attempt to exert control over this aspect of their lives, perceiving it as their only means of managing their life.
Sexual Orientation and Gender Identity Sexual orientation, gender identity and gender norms influence people with eating disorders. Some eating disorder patients have implied that enforced heterosexuality and heterosexism led many to engage in their condition to align with norms associated with their gender identity. Families may restrict women's food intake to keep them thin, thus increasing their ability to attain a male romantic partner. Non-heterosexual male adolescents are consistently at higher risk of developing disordered eating than their heterosexual peers for various body image concerns, including worries about weight, shape, muscle tone, and definition. Eating disorders in trans and non-binary adolescents are complicated in that some eating disorder symptoms may affirm gender identity in transitioning patients, complicating treatment. For example, loss of menstruation in birth-assigned females or a slender frame in birth-assigned males may align with their gender identity during transition. Physicians may fail to diagnose eating disorders in transitioning/transitioned patients mainly because the complex dynamic between gender identity and disordered eating is misunderstood. Furthermore, the leading driving factor of eating disorders in gender diverse patients is gender dysphoria given that both conditions are aligned with dissatisfaction with one’s body. It is possible that disordered eating behaviors may be utilized as a way to change the body to better fit into the aspects of a wanted gender identity. Despite this connection, gender dysphoria often goes undetected likely due to limited provider training and lack of gender affirming care practices, eventually leading to an under diagnosis or misdiagnoses of eating disorders within transgender individuals. Additionally, in treatment, approaches to aid are often not appropriately designed for transgender individuals. For example, patients oftentimes are given standardized calorie recommendations that overlook patients’ concerns as well as go against the sufficient amount of calorie intake needed. == Mechanisms ==