Obesity is a common health risk affecting over 13% of the world’s adult population.(1) Kingdom of Saudi Arabia (KSA) was ranked the fourteenth highest country with obesity rate worldwide in 2016.(2) In the same year, the overall percentage of obesity has reached 35% among Saudis. In addition, in the last three decades, the mean body mass index (BMI) of the KSA population has jumped to the overweight category compared to previously being normal.(3) The substantial increase in obesity rates among Saudi population could be explained by various factors, mainly unhealthy eating habits and sedentary behaviors. One of the biggest causes of sedentary behavior nowadays is the increase in screen use which is due to the rise in electronic devices ownership.(4–8)
The prevalence of electronic devices ownership as well as the duration of using them is increasing globally. Women in the United States of America (USA) spend an average of 6 to 20 hours per week watching television (TV).(9) More than 85% of university students across Canada owns it while in South Korea and KSA it is 100%.(10–12) USA college students spent an estimate of nine hours per day using their smartphones.(4) while more than half of university students in Indonesia spend 5 hours or more a day.(13) In the gulf region, United Arab Emirates (UAE) college students use their smartphones for a mean of 7.5 hours daily.(7) Studies in KSA from universities in Riyadh, Qassim, Jeddah, and Dammam cities have measured the mean time spent on smartphones among college students which were estimated to be 7.5 hours, 3.5 hours, 5 hours, 8.5 hours respectively.(6, 8, 14, 15) The increase in smartphones usage could be explained by its various advantages.
Mobile devices show a positive influence on different aspects of life. Easier access is provided for both consumers and sellers via internet commerce.(16, 17) Many adults spend their screen time for work-related tasks and educational purposes.(6, 10, 13, 18, 19) Laptop classrooms enhance learning by increasing interest, participation, and motivation compared to regular classrooms.(20) To add on, social media is used for sharing information and knowledge among students.(12) Smartphone messages and applications have also shown promising influences on health via promoting preventive behaviours, reducing stress, increasing mindfulness and self-compassion.(21, 22) Moreover, wearable devices connected to a smartphone applications have helped in monitoring the progress and response of patients.(23, 24)
Despite the advantages of screen use, it could have a negative impact on life. Addiction to smartphones is a phenomenon that is significantly increasing especially among young adults(4–8), this has resulted in higher rates of reported low self-esteem, decrease in social behavior(7, 25) and high levels of stress.(8, 26) Moreover, depressive symptoms are more commonly seen in addictive smartphone users. Smartphones could also be a source of distraction during classes.(12, 27) Prolonged screen use is associated with poor academic performance, poor sleep quality, a decrease in sleeping time(6, 14, 15) in addition to greater physical discomfort.(20) Screen usage encourages sedentary behaviors via various mechanisms.(5, 6, 9, 19, 25)
Numerous studies have linked screen use with an increase in body weight by encouraging sedentary behaviors. Prolonged setting time, decreased physical activity and unhealthy eating habits are the main mechanisms behind weight gain.(5, 6, 8, 9, 19, 25) Increased time spent on viewing TV was significantly associated with increased body weight in adults.(28) There is a 23% increase in obesity risk for each 2 hours per day spent on TV. In addition, women who watched TV for longer hours consumed more calories in the form of red and processed meat, saturated fats, and snacks.(9) About 30% of college students agree that after using a smartphone, they started to eat more junk food and gained more weight.(6)
In contrast, other studies suggest that screen use helps in losing weight. Mobile health (m-health) involves using technology to provide interventions that help in improving the patient's lifestyle via personalized contact. This technique has proven its effectiveness in a meta-analysis by Seong-Hi et al where it showed a significant reduction in both body weight and BMI regardless of the duration of the intervention.(29) In another meta-analysis, Fangchao et al have concluded that when using a smartphone intervention that includes either short message service (SMS), Multimedia materials (MMS) or both combined, a significant reduction in weight and BMI can be achieved.(30) When a smartphone intervention was used, total daily steps have increased by 15% and it was associated with decreased BMI(31). Besides that, vigorous physical activity was found to be higher among college students who are using devices connected to a smartphone application. (32)
In conclusion, some studies suggest that smartphones use decreases body weight and hence BMI. This is linked to the use of applications and messages that encourage healthy actions. On the other hand, other studies suggest that screen use increases body weight by encouraging sedentary behavior and unhealthy eating habits. Therefore, the relationship between ST and weight changes is still inconclusive and further evaluation is needed. Therefore we designed this study to “investigate the relationship between ST and BMI in young adults”.