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The night eating syndrome (NES) was first described in 1955 as a disorder characterized by morning anorexia, evening hyperphagia, and insomnia among obese individuals characterized by unsuccessful weight management. NES appears to be associated with obesity. This study was primarily undertaken to study the prevalence of NES.
Three humdered out of a total of 400 undergraduate medical students voluntarily participated in this cross-sectional survey conducted online (self-rated) at a reputed university in Kingdom of Saudi Arabia. Socio-demographic details were recorded on a semi-structured performa. SCOFF was administered to find those at risk of eating disorder. Night eating syndrome questionnaire (NEQ) was used to screen those who had NES.
Nearly, 58% of the sample was male. The mean weight of the total sample was 70.23 (males 79.15 and females 57.9). The mean body mass index (BMI) was 25.09 for male and 22.64 female. Nearly, 21% were found to be overweight and 14.3% were obese. The prevalence of NES in the study was 10.3% with comparatively men being at higher risk for NES.
High prevalence of obesity and overweight in the sample was similar to what has been reported in the Saudi population. Comparatively, high prevalence of NES was found in this study but it was not associated with BMI.
Night eating syndrome, medical student, Saudi Arabia.
The night eating syndrome (NES) was first described in 1955 as a disorder characterized by morning anorexia, evening hyperphagia, and insomnia among obese individuals characterized by unsuccessful weight management . According to the fifth edition of the diagnostic and statistical manual of mental disorders (DSM-5), feeding and eating disorders encompass three main diagnoses, namely, anorexia nervosa, bulimia nervosa, and binge eating disorder. However, the collection of disturbances of eating attitudes and behaviors include several other conditions such as pica, rumination disorder, purging disorder, atypical anorexia and bulimia nervosa, subthreshold binge eating disorder, and NES . NES was included in the DSM-5 as an “Other Specified Feeding and Eating Disorder” characterized by “recurrent episodes of night eating, as manifested by eating after awakening from sleep or by excessive food consumption after the evening meal . In a trans-diagnostic perspective, all these conditions underscore key similarities across the eating disorders, including dietary restraint, binge eating, compensatory purging, body checking, and weight preoccupation.
The prevalence of the NES was estimated to be 1.5% in the general U.S population, and in Omani adult population, 1.5% met criteria for NES [3,4]. The NES appears to be associated with the obesity. Obesity is the most common nutritional disorder in the developed countries. It is a serious, chronic disease that can have a negative effect on many systems in the body and much greater risk of developing serious conditions, including heart disease, type 2 diabetes, bone and joint disease. In the United States, approximately 35% of women and 31% of men are considered seriously overweight, while 15% of children between the ages of 6 and 19 are overweight . The overweight in Saudi population was found to be 27.23% and 25.20% in the adult males and females, respectively, while prevalence of obesity in Saudi Arabia population was 13.05% and 20.26% in the adult males and females, respectively . Compared with the general community, it is evident that NES is more prevalent in populations with weight-related issues. Although many studies observed a positive relationship between NES and body weight [5,6], many others have not [7,8]. Moreover, several studies examined the prevalence of NES across groups of varying body weight [9–13]. Among these studies, all have reported a higher prevalence of NES among overweight/obese group.
Furthermore, young adults have been found to have higher prevalence of evening hyperphagia than any other age group. Particularly, university students who reported high stress, inconsistent sleep patterns, and disordered eating might be at particular risk for developing NES symptoms. The prevalence of NES using proposed diagnostic criteria was reported as 5.7% in one university sample yet few studies have comprehensively explored the significance of night eating in this group especially in this country. Hence, this study was aimed at finding the prevalence of NES in the young adults and its association with obesity and overweight.
Materials and Methods
This study was an online self-rated cross-sectional survey conducted on medical students at one of the reputed universities in the Kingdom of Saudi Arabia. Data was collected over a period of 1 month in the year 2017. The students voluntarily participated to fill in a semi-structured performa including items like gender, age, height, and weight.
Night eating questionnaire (NEQ)—The NEQ was used to screen those who have NES. It is a validated scale for assessing NES that is administered as a self-report questionnaire containing 14 questions about symptoms rated on a 5-point Likert-type scale, which are then summed to obtain a NEQ Global Score. A total score ≥25 has been proposed as a lenient threshold for NES and ≥30 as a more stringent one. For the purpose of this study, the cut-off score chosen was 25 .
SCOFF was administered to find those who are at risk of eating disorder. This scale uses five simple screening questions and has been validated in specialist and primary care settings. It has a sensitivity of 100% and specificity of 90% for anorexia nervosa. Though not diagnostic, a score of two or more positive answers should raise your index of suspicion of a case, highlighting the need for more detailed history.
SPSS version 24 was used. p value less than or equal to 0.05 was considered to be significant. Frequencies and percentages were found for the qualitative variables. Mean and standard variation was found for the quantitative variables. Chi square test used to find the relationship between qualitative variables.
Out of 400 students, 300 volunteered to participate in this online questionnaire-based study. Nearly, 58% were males and 42% females. Nearly, 90% of the sample was between 20 and 25 years of age. The mean weight of the total sample was 70.23, for males it was 79.15 and for females it was 57.9. The mean body mass index (BMI) was 25.09 for males and 22.64 for females. Out of 300 students, 26% were found to be overweight, 16% were obese, and 5.7% were under weight.
Nearly, 67% of the sample was found to be at risk for eating disorders as per the SCOFF questionnaire. Surprisingly, more male students were positive on SCOFF but the difference was not statistically significant. SCOFF was significantly more positive in those who were overweight and obese as compared with those having normal BMI and who were underweight.
Thirty one out of 300 (10.3%) had scored more than 25 on NEQ which was the cutoff used to suggest presence of NES. More males were found to be positive for NES as compared with females but the difference was not significant. Though more students positive for NES were found to be overweight, there was no significant relation between NES and BMI.
This study was primarily aimed at finding the prevalence of NES in young university students and high rates of NES were found (10%) in this study as compared with relatively low rates reported in the general population of around 0.5% to 1% [3,4]. One study done in Oman found the prevalence of NES in the general population to be 1.5% . The nearest prevalence rate of NES of 5.7% was reported by Nolan et al. , and one in which NES was diagnosed by both survey and semi-structured interview in university students  using the same diagnostic criteria. This difference in the prevalence rates could be explained because the study sample was not representative of the general population and the cut-off score of 25 on NEQ chosen for this study was considered quite liberal as compared with the score of 30 which was considered more restrictive. Besides young adults have been found to have more prevalence of evening hyperphagia as compared with any other age group and added to that a high level of perceived stress, inconsistent sleep patterns, and disordered eating make good ingredients for the development of NES in this population [21–24].
Based on the evaluation done with SCOFF, more than half of the sample was found at risk of having eating disorder along with the high prevalence of obesity and overweight found in the study (similar to that found in the Saudi general population) suggested a possibility of binge eaters being more in the study sample. Since different types of eating disorders are phenomenologically similar and are considered as secondary epiphenomena [26,27] to a more profound psychopathological core, defined by excessive concerns about body shape and weight hence follow-up interview of those screened positive for NES becomes necessary to differentiate it from binge eating in the absence of which the rates of NES could get inflated [28,29].
There was no significant difference in the rates of NES with respect to gender in keeping with another study done on general population where no association was found between positive NES screening result and any of the socioeconomic parameters like age, sex, marital status, education, employment status, and area of living .
The high prevalence of overweight and obesity among Arab countries and as was reflected in the present study as well, is attributed to multiple factors including rapid nutritional transition, high socioeconomic status, physical inactivity, and genetic admixtures [10,11]. Eating behavior and circadian rhythm are proving to be important factors in the etiology of obesity. In obese individuals, NES is more frequent and the majority of patients undergoing bariatric surgery may have NES  but in spite of this no significant association was found between any of the four categories of BMI (underweight, normal, overweight, and obese) and being NES positive. This finding goes along with several studies, which have conclusively proven that the relationship between BMI and NES was determined by the age [19,20]. One of the study found that the night eating was positively associated with BMI in participants who were between 31 and 60 years old, but not in younger (<31 years) or older (>60 years) participants. That is, weight gain may only occur after longer periods of engaging in night eating and, thus, no or only small relationships can be found in younger samples such as students .
There were some limitations of the current study like all data were based on self-report, which may inadvertently affect the data quality. For example, it is known that self-reported height and weight are biased such that the height is usually overestimated and weight is underestimated. Another limitation was that this was a cross-sectional study and, thus, causal relationships cannot be inferred. A large scale population based prevalence studies are needed to find the precise rates of NES affecting the general Arab population. Further longitudinal studies need to be done to understand the exact impact of night eating and evening hyperphagia over a period of time.
NES seems more prevalent in the Saudi young adult population, and hence more awareness is needed amongst people about NES right from the early life; as the consequences of NES are generally seen later in life as reflected in this study, where in spite of high prevalence of obesity and overweight in the sample, there was no positive association between weight and presence of NES.
List of Abbreviations
NES Night eating syndrome
NEQ Night eating questionnaire
DSM Diagnostic and statistical manual of mental disorders
Consent for publication
Informed consent was obtained from participants.
Declaration of conflicting interests:
The authors declare that there is no conflict of interest regarding the publication of this article
Shakeel Ahmed1, Fahad Salman Al Harbi2, Osama Al Saeed1, Sayed Ibrahim Ali3,4
Department of Clinical Neurosciences, College of Medicine, King Faisal University, Hofuf, Saudi Arabia
College of Medicine, King Faisal University, Hofuf, Saudi Arabia
Department of Family Medicine, College of Medicine, King Faisal University, Hofuf, Saudi Arabia
College of Education, Helwan University, Helwan, Egypt
American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. DSM 5. Washington, DC: American Psychiatric Publishing; 2013.
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How to Cite this Article
Ahmed S, Harbi FSA, Saeed OA, Ali SI, . Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. IJMDC. 2019; 3(1): 22-25. doi:10.24911/IJMDC.51-1544294177 Web Style
Ahmed S, Harbi FSA, Saeed OA, Ali SI, . Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. https://www.ijmdc.com/?mno=20804 [Access: January 28, 2022]. doi:10.24911/IJMDC.51-1544294177 AMA (American Medical Association) Style
Ahmed S, Harbi FSA, Saeed OA, Ali SI, . Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. IJMDC. 2019; 3(1): 22-25. doi:10.24911/IJMDC.51-1544294177
Ahmed S, Harbi FSA, Saeed OA, Ali SI, . Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. IJMDC. (2019), [cited January 28, 2022]; 3(1): 22-25. doi:10.24911/IJMDC.51-1544294177
Ahmed, S., Harbi, . F. S. A., Saeed, . O. A., Ali, . S. I. & (2019) Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. IJMDC, 3 (1), 22-25. doi:10.24911/IJMDC.51-1544294177
Ahmed, Shakeel, Fahad Salman Al Harbi, Osama Al Saeed, Sayed Ibrahim Ali, and . 2019. Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. International Journal of Medicine in Developing Countries, 3 (1), 22-25. doi:10.24911/IJMDC.51-1544294177
Ahmed, Shakeel, Fahad Salman Al Harbi, Osama Al Saeed, Sayed Ibrahim Ali, and . "Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia." International Journal of Medicine in Developing Countries 3 (2019), 22-25. doi:10.24911/IJMDC.51-1544294177
MLA (The Modern Language Association) Style
Ahmed, Shakeel, Fahad Salman Al Harbi, Osama Al Saeed, Sayed Ibrahim Ali, and . "Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia." International Journal of Medicine in Developing Countries 3.1 (2019), 22-25. Print. doi:10.24911/IJMDC.51-1544294177
APA (American Psychological Association) Style
Ahmed, S., Harbi, . F. S. A., Saeed, . O. A., Ali, . S. I. & (2019) Prevalence of Night Eating Syndrome amongst Medical Students in Saudi Arabia. International Journal of Medicine in Developing Countries, 3 (1), 22-25. doi:10.24911/IJMDC.51-1544294177