Eating disorders (EDs) are defined by the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM-V) as illnesses characterized by severe disturbances in eating behaviors. According to the DSM-V, the following EDs are recognized: anorexia nervosa, bulimia nervosa, binge eating disorder, and other not-specified eating disorders as distinct disorders within this group (1).
It appears that EDs have been on a steep rise in the last five decades and that the percentage of women suffering from EDs is higher compared to men of all ages (2). Thus, the incidence of EDs among males and females is 10:3 during adolescence and 20:1 in young adults (3, 4). Although EDs are more common among women, epidemiological studies indicate that the prevalence of men at high risk of EDs has increased in recent years (5) and that many similarities have been found between men and women in risk factors for EDs (6). Yet, it should be noted that the number of men who are reported to have EDs is lower than the actual number, as the social and gender stigma associated with EDs may cause some to deny the presence of symptoms (7).
Most studies investigating EDs have focused on adolescents (e.g., 2). Recently it was observed that the incidence of EDs in the period of young adulthood had risen sharply (8). Moreover, young adults' treatment needs are less well met than adolescents' (8, 9). However, there is a paucity of research examining the risk factors of EDs in this age group. Examining the factors that increase the risk of developing EDs in both women and men in young adulthood may be the key to understanding and treating EDs during this age group.
One of the main risk factors of EDs is emotional distress. People who suffer from emotional distress (i.e., stress, anxiety, depression) are more vulnerable to developing EDs (6, 10). Individuals with high levels of disordered eating attitudes and behaviors have been found to be highly avoidant of emotions, reporting higher levels of sensitivity and intensity to emotional arousal (11). Thus, for example, one of the negative consequences among people suffering from depression is the development of problematic or pathological thinking and behavior regarding eating (12).
As claimed by Kerr and Bowen (13), who led the Family Systems Theory, emotional distress may stem from family patterns acquired in childhood, affecting intrapersonal and interpersonal functions. They suggested that one of the main patterns is Differentiation of Self (DoS), a personality and family focal pattern passed down from generation to generation and has a significant influence on the development of individuals' emotional and physical health. DoS is expressed on two levels: the interpersonal level describes the ability to balance intimacy and autonomy. The intrapersonal level taps the ability to balance the rational and emotional realms when coping with stressful situations. It includes four metrics: emotional reactivity, I-position, emotional cut-off, fusion with others. People who are poorly differentiated tend to be overwhelmed when dealing with stressful situations (i.e., emotional reactivity) and have difficulty expressing their thoughts and feelings and sticking to their desires (i.e., I-position). When emotionally overwhelmed, they try to decrease their anxiety either by disengaging physically and emotionally without facing the difficulty (i.e., emotional cut-off) or by creating dependent and symbiotic relationships (i.e., fusion with others).
There is evidence that poorly differentiated people are likely to suffer from high levels of emotional distress (14, 15). These results suggest that low levels of DoS may lead to misinterpretation of stressful situations that can increase mental distress, self-doubt, and depression. In turn, this can lead to distorted self-perception, channel the feelings to extreme weight or eating (16), and increase eating pathologies aimed at improving body image (12). However, only a few studies have examined the relationship between DoS and EDs. For example, DoS was found associated with EDs in samples of male college students (17) and adolescents (10).
A low level of DoS was found to increase vulnerability to emotional and physiological pathologies by increasing susceptibility to psychological distress among adolescents (6), young adults (18) and adults (14). However, there is no evidence that emotional distress mediates the relationship between DoS and the risk of EDs among young adults to the best of our knowledge. The sharp increase in the risk of EDs among people in this age group raises the need to examine this issue.
Therefore, the current study was conducted among young adults. Studies have indicated a significant change in how developmental psychologists understand the transition from childhood to adulthood (19). Historically, it was assumed that adulthood is achieved at the age of 18 (20). However, due to social and economic changes, many of the critical milestones of adulthood (e.g., marriage, parenthood, homeownership) are being reached much later than in previous decades (19). According to Arnett (21), the transition to adulthood is characterized by changing feelings and multiple experiences that young people try to explore before deciding about a clear and cohesive way of life. In addition, there is evidence that they face emotional, interpersonal, and familial challenges during this period and often suffer from various emotional disorders, one of which is EDs (8).
Taken together, the findings suggest that DoS may increase vulnerability to EDs by increasing susceptibility to emotional distress among young adults. Thus, and given the evidence of associations between EDs and emotional distress, as well as between emotional distress and DoS, the primary purpose of this study is to map the complex relationships between the risk of EDs, emotional distress and DoS among young adults. Therefore, it is reasonable to hypothesize that emotional distress (stress, anxiety, depression) will mediate the relationship between DoS (emotional reactivity, I-position, emotional cut-off, and fusion with others) and risk of EDs (drive for thinness, bulimic tendencies, body dissatisfaction, and perfectionism). In addition, based on findings indicating a higher risk of EDs among females (4), we aimed to examine whether there are gender differences in the research indices as well as in the mediation model.