Our results revealed 85.5% of Zahedan university students consume fast foods at least once every month and 68.1% consume soft drinks at least once every month. There are few recreational, entertainment, and sport facilities in Zahedan, which may account for the high consumption of fast food by Zahedan university students. We found that FFC in our study was more than other studies [14, 17]. Results of studies in students of two largest universities in Qom, center of iran, reported that more than 72% of people used fast foods monthly that was lower than our estimate [18]. but, a same study in medical students showed that 64% had FFC for two or more time per week [14]. The obesity prevalence in our study was estimated 19.9% (based on BMI or WHtR or WC). In a previous study, the obesity/overweight prevalence was 21.3% and nearly three quarters of them used fast foods [1]. According to our results, obesity based on WHtR and WC was significantly different between subjects who used and not used fast foods while the difference in BMI was not significant. It has been shown in some studies that FFC is associated with overweight and obesity [7, 19–22]. Fast foods are poor in micronutrients, high in trans fatty acids, low in fiber, high in energy density, high in glycemic load and large portion size and could be more energetic than the daily energy requirements [8, 23].
In addition, according to our findings, SDC was related to obesity (based on BMI or WHtR or WC). There are several reasons why SDC may cause weight gain, including low satiety of liquid calories and incomplete replacement of energy at subsequent meals [24]. Forthermore, due to their high glycaemic index, soft drinks can increase caloric intake and promote excessive weight gain [25, 26].
A number of noncommunicable diseases are linked to obesity, including hypertension, hyperlipidemia, hypercholesterolemia, cardiovascular disease, metabolic syndrome, and type 2 diabetes [2, 3, 27, 28]. Increase in energy density and trans fatty acids of diet, together with concomitant eating behaviors like FFC and SDC, promote unhealthy weight gain through passive overconsumption of energy and increase of fatty acids intake [29, 30]. Increase of dietary intake of trans faty acids can significantly alter serum levels of adipokines [31]. For example, in study of Zhiliang Huang et al, increase consumption of trans fatty acids by wistar rats, significantly increased serum levels of adiponectin, resistin and decreased serum levels of leptin [32]. The adipokines play an important role in regulating appetite, glucose and lipid metabolism, inflammation, and resistance to insulin and altering to their serum levels can lead to metabolic disorders [33].
Similar to our study, begum R et al did not find any significant association between BMI and FFC in their study [15]. In our study, we found that prevalence of obesity based on BMI was significantly higher in females, while the prevalence of FFC was not associated to type of sex. Moreover, four variables including job status, type of university and education level and mothers education level are the most associated factors of FFC. Based on our results in multivariate model, both have a job and study at medical sciences university increase the odds of FFC near two fold and more than two fold respectively.
The higher fast foods consumption in Students who were employed and students in the medical sciences university might related to lack of time to cook healthy foods [34]. Since medical students have an increased study load and spend a lot of time in hospitals, they have less time to cook healthy foods and it is more convenient for them to eat fast foods [35]. Additionally, in our study, students mentioned value/cost and taste/deliciousness as the main reasons for eating fast foods. Similar to our findings, these results were also reported in the study of Driskel et al [36].
The present study has several strengths in its procedure: At first, Until now, no detailed studies have been conducted on FFC among zahedan medical and non-medical students; second, We had a sufficient sample size in our study and third; A potential confounder adjustment was conducted. However, there are some limitations to the present study. First, Students' morphometric characteristics and adiposity measurements could not be accounted as body composition indexes, second, another limitation of this study was the lack of cooperation from students when it came to anthropometric measurements, third, the modified form of the NELSON’s fast food questionnaire does not provide questions about the quantity and quality of fast food consumed, and fourth, the frequency of FFC was determined based on self-report, which may be influenced by recall bias.