To the best of our knowledge, the current study was the first to estimate the prevalence of NES, and to explore the relationship of NES with sociodemographic characteristics, medical history, lifestyle habits, BMI, and Mental health among Palestinian university students. Because this study was observational, clinical interviews were not carried out to diagnose NES; rather the night eating questionnaire (NEQ) was used to assess the percentage of students who reported behaviors and symptoms consistent with the diagnostic criteria for NES.
In the analysed sample, many university students had a high NEQ scores. By using the NEQ ≥ 25 cut-off point, the prevalence of NES among the current sample reached 29.7% higher than the evaluated proportion of NES for the general population which was 1.1% [28], and higher than the evaluated prevalence for other countries of university students; 5.8% Egypt [29]Turkey 9.5% [4], United states 4.2% [5], China 1.6% [6] and Brazil 15% [30]. Even though the aforementioned research utilized the same instrument and cut-off values, the outcomes varied significantly. This disparity is mostly attributable to variances in each community’s way of life, the learning and teaching approaches at colleges, socioeconomic status as well as the sample size. It is important to note that the current study was conducted following the COVID lockdown, which had a significant impact on Palestinian university students’ eating habits and lifestyle [31]. This high prevalence of NES, according to the authors, may be related to the fact that students are still impacted by these changes. Moreover, This result may be attributable to the availability of late-night restaurants in Palestine, which permits students, to dine out at night to converse or watch sports games while ordering food.
Other possible explanations for the high values of NES include the fact that students with higher personal incomes recorded a significantly larger proportion of NES (42.7%). As well as students who do not have a scholarship or financial help from their parents, a larger proportion of NES (54.3%) was recorded. As it was noticed that NES was more likely to occur among students whose studies were funded by means other than parents or scholarships. Other means can be the student himself, and in this case the student has to work in the night in order to fund his studies. Hence, working in the night while studying during the day puts a lot of pressure or maybe anxiety on the student leading to nocturnal eating. This could explain the current result.
Both indicators may suggest that these students are working at night to earn money, which may influence their eating habits and cause them to become night eaters.
The vast majority of NES assessments among university students propose that the percentage of its occurrence is higher than in the general population. Except for one German study reported that the prevalence of NES among a sample of students was within the range of 1.1 to 1.5%, which is prospected for the general population [32]. As the literature lacks studies conducted inside the Palestinian community, a comparison between university students and Palestinians requires additional investigation. This finding may also explained by the availability of late hour restaurants in Palestine allows students to dine out conveniently at night to chat together or watch sports games together in a group while ordering food to eat, especially among males.
Regarding the relationships between university students with NES and those with no NES, the current findings revealed that there were no significant differences in terms of BMI, physical activity, and smoking status. Similar results were also indicated in former studies [5, 18, 29, 33].
There are established theories explain the relationship between night eating practices and weight gain[34]. A comparison of the circadian rhythms of leptin, ghrelin, glucose, and insulin in people with NES and healthy controls revealed disruptions in the rhythms of leptin, ghrelin, glucose, and insulin among night eaters as compared to normal [35]. This disruption has been linked to obesity, and metabolic irregularities cause changes in physiological systems that might have a negative impact on health.[34] Despite these findings, conflicting data linking NEs and BMI has been presented. Bruzas and Allison (2019) reviewed 11 studies that investigated the relationship between NES and BMI, five of these studies indicated a significant association between the two variables, five demonstrated that there was no relationship, and one provided mixed data. [36] A Negative eating habits indicate long-term weight gain and a high BMI. [37] As the current study sample consists of young individuals, it appears that their eating behavior has not yet affected their weight. Other possible explanations for the lack of association include energy balance, overall caloric intake, and the caloric density of foods consumed at night.
Another notable finding in this study is that there is a statistically significant relationship by using univariate and multivariate analysis between gender and NES prevalence among the studied students as it was noticed that males had a relative higher occurrence of NES than females. This result comes in agreement with former studies done by He et al., (2017) [6], and Colles et al., (2007) [38], however, it is inconsistent with other studies that indicated no gender differences [4, 7, 32]. Since gender composition was not evenly distributed in the current sample, the result of a significant association between NES prevalence and gender may necessitate further studies in the future.
Besides, students from scientific background possessed a higher risk of developing NES than students with humanities background was found. The finding contraindicates a Malaysian study which found that students who were studying technical majors were at a greater risk of developing NES compared to students who were studying either scientific or humanities majors.
Both multivariate and univariate analysis showed that NES occurrence were found to be significantly associated with mental problems (psychological distress, emotional dysfunction, and cognitive disorder). This is in line with the findings from former studies [4, 6, 30]. It was found in a former study conducted on 849 Chinese college students that the prevalence of NES was significantly and positively related to psychological distress [6]. Furthermore, Sevincer and his colleagues that NES scores was significantly and positively associated with depression and anxiety symptoms [4]. In addition, the emotional state of Brazilian university students was significantly associated with the behaviors of NES syndrome [30]. Our finding indicates that it is relatively prevalent for students with NES to have mental problems (psychological distress, emotional dysfunction, cognitive disorder). However, it stills obscure whether mental problems is a clinical feature, cause, or a consequence of NES. Further studies are warranted to explore the exact relationship between mental problems and NES.
The study has several limitations that should be mentioned. First; since the current study is considered a cross-sectional, it does not permit casual inferences. Second, since the current study only included undergraduates from three universities in the southern part of Palestine, therefore the findings might not be representative for undergraduates in the whole Palestine. Third, the collected data was self-reported, thus there may be incorrect or biased data provided by undergraduates. Lastly, undergraduates’ participation were self-chosen and not compulsory. This sampling technique may result in a “selection bias” concerning undergraduates’ attention in completing the questionnaire as undergraduates with disordered eating pattern may not have participated in this study, giving rise to underestimation in the proportion of undergraduates having symptoms congruent with NES in the current study. Nonetheless, this study is the first of its kind in providing a worthy data about the prevalence of NES among university students and its’ association with lifestyle variables. Future studies should focus on clarifying the causal relationship, and assess nutritional for a better understanding of the NES. Further studies should also be conducted on a large sample size.