Adolescence period is frequently accompanied with special types of problems including body dissatisfaction and disturbed eating behaviors. Adolescent eating disorders are usually having a chronic course and associated with serious psychiatric and medical co-morbidities and complications [23].
In the current study, the prevalence of eating disorders (EDs) in a representative scholastic sample was evaluated, and demographic and clinical factors associated with ED were assessed.
The results showed that male participants were significantly (P ≤ 0.0001) heavier and taller than their female counterparts. These data are concordant with the general view that males were significantly heavier than females from various studies all over the world [24, 25].
The difference between males and females with regards to body weight could be explained with many biological factors like lower total muscle mass in females than males [26]; males convert more of their caloric intake into muscle, while females tend to convert more into fat deposits [27]. In addition, the greater muscular mass in males is described to be due to muscular hypertrophy as a result of higher levels of circulating testosterone in their blood [28].
Unsurprisingly, the current study showed that female students are significantly more preoccupied with their body shape (BSQ-R-10 = 31.68 ± 13.81) than their male counterparts (BSQ-R-10 = 25.63 ± 11.60). These data are in agreement with the results of previous studies which indicated that adolescent females significantly put greater importance of both body weight and shape on self-evaluation than males [29,30,31,32].
On the Eating Attitude Test (EAT), we found that 9.3 % of Egyptian adolescents had a tendency for disturbed eating behavior. Mintz and O’Halloran (2000) [33] reported a high specificity rate for the EAT-40 with an accuracy rate of at least 90% when used to differentially diagnose those with and without eating disorders. It also has an accepted discriminant capacity between clinical and non-clinical samples. This was replicated in the current study, which revealed that all (EAT-40) positive scorers were proved to have a full threshold eating disorder by SCID-1 interview.
These results are consistent with those of other Egyptian studies [17, 34, 35]. Moreover, our results also agreed with the results of many other studies in Arab and Western countries [36,37,38].
However, the results of a study investigating the eating disturbances among adolescent school girls in Jordan reported that eating disorder occurrence in a population sample using DSM-IV-TR diagnostic criteria is 33.4% which is higher than that observed in both Western and non-Western world [39]. Other studies reported much lower prevalence rates of eating disorders in adolescence. For example, Swanson and his colleagues found that eating disorders are prevalent in 3% of their adolescent samples [40]. These differences between various studies may be due to the variabilities in sample size, study setting and design, and the studies’ targeted age and gender groups.
Moreover, the current study showed that bulimia nervosa is the commonest type of eating disorder encountered in the study sample (6.1% (25) students), while 3.2% (13 students) were having anorexia nervosa.
Although, the most common diagnosis of eating disorders among adolescents is Eating Disorder Not Otherwise Specified (EDNOS), the current study did not find any students with that diagnosis. The reason behind that may be due to the specific psychometric properties of EAT-40 with its ability to differentiate between threshold, subthreshold, and undifferentiated forms of eating disorders, with an accuracy rate of at least 90%. These results were found during the EAT-40 validation with DSM-IV eating disorder criteria [33]. It is consistent with the findings of this current study that all students with abnormal eating attitudes and behaviors (with EAT-40 score ≥ 30) have an eating disorder which was further confirmed by SCID-I.
Contrary to our study, other previous studies revealed lower prevalence rates for anorexia nervosa among adolescents. Prevalence of anorexia nervosa varied from 0 to 1.7% in previous American and European studies [41,42,43,44,45].
For a long time, anorexia and bulimia have been classified as a Western disorder or the disorder of the developed world, but the current study results clearly demonstrated that this assumption might not be true and confirmed the results of some other studies, which reported that the level of eating disorders is rising in the developing countries [46].
The higher estimate of AN in our study may reflect the highest level of underestimation of such disorders among this age group. This could reveal the huge magnitude of such mental health problems with decreased awareness of these disorders and limited access to health care specialists and appropriate interdisciplinary teams.
On the other hand, the prevalence of bulimia nervosa differs widely across different studies, with estimates ranging from 0.9 to 4.6% [44, 47, 48]. In a previous Egyptian study, bulimia nervosa was prevalent among 14 adolescent secondary school students (6.8%) from a total of 205 students [35] which is consistent with the finding of the current study (6.1%).
Assessment of sociodemographic factors associated with eating disorders among Egyptian adolescents revealed that they are notably prevalent in females than males (82% of them were females and 18% were males), which is consistent with other various studies [49, 50]. Girls are more likely than boys to have weight and body dissatisfaction, body image concern, and dieting for weight control [30, 32].
Adolescence obesity/overweight and weight fluctuations may be considered as a risk factor for eating disorders later on in adulthood. Overweight girls showed some of the psychological features associated with the development of EDs, including a link between concerns and self-esteem based on physical appearance [51]. Our study showed a higher mean body weight and body mass index among students with eating disorders than those without eating disorders. Further longitudinal follow-up studies are needed to demonstrate the relation between childhood body weight, BMI, and later development of eating disorders in adolescence.
Body shape and self-esteem play an important role in the development of eating disorders in adolescence [52]. Our data are highly concordant with this finding, as 68.4% of Egyptian students with eating disorders are highly preoccupied with their body shape in comparison to those without eating disorders (15.4%) with a highly significant statistical difference between them. In addition, students with eating disorders a have highly significant lower self-esteem (mean self-esteem score = 25.92 ± 5.97) than students without eating disorders (mean self-esteem score = 41.06 ± 8.00).
In agreement with other studies [38, 53, 54], our study showed that female gender, overweight (BMI = 25–29.9 kg/m2), low self-esteem, and high body shape preoccupation are significant predictive factors for the occurrence of eating disorders among adolescents.
One significant strength of our study was derived from using a representative sample, having high initial participation rates and low attrition rates, which closely represented the broader adolescent population.
Various limitations should also be considered in interpreting our results. First, being a cross-sectional design did not allow us to get causal inferences. Further longitudinal studies are required to confirm the cause-effect relationships. Second, the use of (EAT) may limit the detection of students with subthreshold symptoms of eating disorders.