Abstract
With technological progress, the use of the internet and smartphones has become an inseparable part of our lives and their use is increasing. The uncontrolled use of both the internet and smartphones is defined as problematic use. This study examined the effects of problematic internet and smartphone use on dietary behaviors and abnormal body weight status in young adults. Participants were 560 university students. Participants completed measures of demographics, dietary behaviors, internet and smartphone usage habits, Young’s Internet Addiction Test and Smartphone Addiction Scale. Negative associations were found between dietary behaviors and problematic internet and smartphone use. Significant inverse associations were also found between these uses and recommended consumption levels of several food groups. For a healthy future generation, it is recommended that policies be developed to prevent or manage these problematic uses, especially in young adults with negative dietary behaviors and abnormal body weight.
Introduction
The internet is a global network that has the ability to increase the accessibility and availability of resources in times of need. As of January 2023, there is 5.16 billion internet users worldwide, which is 64.4% of the world’s population (Statista, 2023). In our country (Türkiye), it was observed that 94.1% of households had access to the internet from home in 2022, and the rate is still increasing (the rate was 92.0% last year). In addition, the rate of internet usage among individuals aged 16–74 was 82.6% in 2021 and increased to 85.0% in 2022 (TurkStat, 2022).
As the number of people using the internet has increased, problematic internet use has also seen a corresponding increase. The term “problematic internet use” is often and commonly used to define individuals who use the internet excessively or struggle to control their use. Although problematic internet use is not included as a psychiatric disorder in the Diagnostic and Statistical Classification of Mental Disorders (DSM)-5 or the International Classification of Diseases (ICD)-11, there has been considerable debate on the topic (Jo et al., 2019). However, most professionals consider problematic internet use as a type of behavioral addiction (Kurniasanti et al., 2019; Panova and Carbonell, 2018).
The devices used to access the internet have changed over time. In the past, internet was generally accessed through computers, but with the development of technology, the use of smaller and more portable devices (such as smartphones, smartwatches, etc.), which can also be used for communication, navigation, news, games, social media and multimedia, has increased even more due to their high mobility and capacity (Vujić and Szabo, 2022). According to published data, adults in our country spend an average of 8 hours per day on the internet, while globally the average is 6 hours and 58 minutes (Kemp, 2022). In addition, recent data shows that the average global user spends 3 hours 15 minutes per day on their mobile phone, whereas in Türkiye this time is 4 hours 16 minutes (Howarth, 2023). The widespread use of the internet and smartphones has revealed some problems due to the increase in usage time (Meng et al., 2022). Although it may seem beneficial for many people to own a smartphone, the literature suggests that there are associations between problematic internet/smartphone use and mental and physical health (Alotaibi et al., 2022), and neurological problems (Elkholy et al., 2020).
In recent years, researchers have shown an increased interest in whether there is a link between the increasing problematic use of the internet or smartphones over the years with the rising rates of poor dietary habits and obesity. However, the number of studies investigating the relationship between problematic internet or smartphone use, dietary behaviors and body mass index (BMI) is scarce and the results are controversial, particularly in the context of problematic smartphone use. Still, there is a debate in the literature about the positive, negative or no relationship between the problematic internet or smartphone use and related eating habits (Ioannidis et al., 2021; Shin et al., 2019). It has also been reported that the age of onset of dysfunctional eating behaviors is between 15 and 25 years of age and it can even be fatal (Hay et al., 2015; Mairs and Nicholls, 2016). In this context, this research was conducted with young adults, who are stated as a risk group. In addition, it is reported that targeted interventions are insufficient due to the lack of information on the factors affecting unhealthy eating behaviors in the literature (Liu et al., 2021).
Therefore, the present study was designed and conducted to investigate the relationship between internet and smartphone addiction with dietary habits and BMI in terms of abnormal body weight status. It is hoped that this study will provide important contributions and interpretations to the conflicting results in the literature. Furthermore, its thought that the our findings are extremely valuable in terms of national and international public health policies planned in the field of nutrition, problematic internet, and smartphone use.
Methods
Desing and participants
In this cross-sectional study, university students were recruited from the faculty of health sciences at the one of the university in Türkiye between June and December 2022 and were required to complete a structured questionnaire. The study data were collected by the researchers using a face-to-face method during the students’ free time (recess, leisure time, etc.) with the questionnaire. The researchers of the study, who are specialists in the fields of nutrition and dietetics and psychology, designed the questionnaire by reviewing the literature and receiving professionals feedback. Before starting the study, a pilot study was conducted for the final version of the questionnaire and the shortcomings were corrected.
Ethical approval for the study was obtained from the ethics committee of the university. A total of 650 university students were invited by simple random method and 560 of them agreed to participate and were included into the study after informed consents. A full explanation was given to all participants who were fully aware of their right to withdraw from participation at any time during the study period. The data were controlled in detail by the researchers, the situations of incorrect or missing answers were noted and these data were not statistically analyzed. Sample size was estimated using G-power software (3.1.0). Based on a previous study in which correlation coefficient between BMI with addiction scores were reported to be 0.121 and 0.179, respectively (Tayhan Kartal and Yabancı Ayhan, 2021). At least 420 participants were required after estimating the condition of a type-I error of 0.05 to a power of 0.90.
Study Questionnaire
The study questionnaire consisted of questions on socio-demographics (age, gender, weight, height, income etc.), dietary behaviors (number of main meals and snack in per day, skipping meals and reasons etc.), consumption of food groups (dairy products, meat, poultry, and fish etc.), internet and smartphone usage habits (use of tools and purposes for both smartphone and internet, internet package etc.), the Young’s Internet Addiction Test-Short Form (IAT-SF) and the Smartphone Addiction Scale-Short Form (SAS-SF). Self-reported weight and height were recorded. BMI was calculated as weight (in kg divided) by height (in meters) squared (kg/m2). BMI was categorized according to World Health Organization criteria: underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30.0) (World Health Organization (WHO), 2019).
Measures
Young’s Internet Addiction Test-Short Form (IAT-SF)
It is a self-report questionnaire, including psychological dependence, compulsive use, and withdrawal, as well as the related problems of school or work, sleep, family, and time management (Young, 2009). The short form of IAT was developed by (Pawlikowski et al., 2013) and adapted into Turkish by (Kutlu et al., 2016). The scale consists of 12 items. IAT-SF is a 5-point Likert-type measurement tool. The scores obtained from the scale vary between 12 and 60. High scores on the scale indicate high levels of problematic internet use. There is no cut off score in the Turkish version. The validity and reliability of the scale was found to be a single-factor structure. In the present study the Cronbach’s coefficient alpha for the IAT was 0.90.
Smartphone Addiction Scale-Short Form (SAS-SF)
The 10-item smartphone addiction scale assessed problematic use of smartphone using 1 (strongly disagree) to 6 (Strongly Agree) scales (Kwon et al., 2013). The Turkish validity and reliability of the scale adapted by (Noyan et al., 2015). The total scores were calculated by adding up all the scores given by the participants on each item and the total score ranged from 10 to 60. A higher score indicates a more problematic smartphone use tendency. There is no cut off score in the Turkish version. The Cronbach’s coefficient alpha in the present study was 0.89.
Consumption of food groups
According to the Turkish Nutritional Guidelines, healthy individuals aged 18–49 years are recommended to consume each food group, that is, dairy products (3 servings/day), meat, poultry and fish (1.5 servings/day), cereals (4–5 servings/day), legumes (3 servings/week), vegetables (2–3 servings/day), fruits (2–3 servings/day), and nuts (0.5 servings/day) (TÜBER, 2016). The standard portion size/amount of the food groups was explained in detail to the participants before they completed the questionnaire. They were asked to select “yes,” “no,” and “partial” for their consumption status.
Statistical analyses
IBM SPSS 25 was used for all statistical analyses. The normality of the data was assessed using the Kolmogorov-Smirnov distribution test. Independent samples t-test (continuous variables) and Fisher’s exact test (categorical variables) were used to analyze the significance of differences between the two independent groups, while one-way ANOVA was used to determine the significance of differences between more than two groups. Post-hoc tests were performed using the Tukey adjustment. In all tables, the numerical variables are presented as mean ± standard deviation (SD) and the categorical variables are presented as number of observations and percentages (%). Hierarchical binary logistic regression analyses to test our hypotheses with normal weight status as the dependent variable. In the hierarchical binary logistic regression, gender, age, income, physical activity and sleep duration were entered in step 1. The problematic internet use score was entered in step 2. The problematic smartphone use score was entered in step 3. Results with p-values of <0.05 were considered to be statistically significant.
Results
Five hundred sixty participants (16.3% males) were recruited with a mean age of 20.6 ± 1.3 years. Participants had a mean BMI of 21.9 ± 3.5 kg/m2, 13.4% and 2.7% of participants were overweight and obese, respectively. Other characteristics of the participants are presented in Table 1.
Descriptive characteristic of participants.
The internet and smartphone usage habits of the participants are shown in Table 2. Almost all of the participants confirmed that they use smartphones as a tool to connect to the internet. The purpose of the participants’ internet use is 75.0% for social sharing, and the purpose of their smartphone use is 73.0% for the internet.
Internet and smartphone usage habits of participants.
More than one answer given.
Independent samples t-test.
Note: Bold text indicates statistical significance.
As shown in Table 3, 62.0% and 42.9% of participants reported eating two main meals and one snack per day, respectively. In addition, more than half of them (52.0%) thought that they were not eating a healthy diet. The SAS score showed a significant difference between the groups according to the reasons for skipping meals (p < 0.05). In addition, IAT and SAS scores were statistically higher among those who thought they were not eating healthy compared to others (p < 0.01).
Problematic internet and smartphone use score by participant’s dietary behaviors.
Note: Bold text indicates statistical significance.
The SAS score was found to be significantly lower in those who consumed 4–5 servings per day of the cereal group compared to those who did not (p < 0.05). Also, the IAT score was statistically significantly higher in those who did not consume 3 servings per week of the legume groups compared to those who did (Table 3).
The IAT and SAS scores of the participants according to BMI classification are shown in Supplemental File. According to the findings, the lowest IAT score was determined in the normal group and the highest in the obese group. A similar situation was observed for the SAS.
Table 4 shows three hierarchical binary logistic regression models to assess the effect of the problematic internet and smartphone use scores, controlling for gender, age and income, for normal weight status (BMI: 18.5–24.9 kg/m2). The models showed no significant differences in age, gender, income, physical activity and sleep duration between weight status groups. Problematic internet use was a significant factor for abnormal weight status in model 2 (OR: 1.057, 95% CI (1.032, 1.084), p < 0.01) and model 3 (OR: 1.036, 95% CI (1.005, 1.068), p < 0.01), with increasing scores increasing the likelihood of abnormal weight status. Adding problematic smartphone use to the model reduces the effect of the problematic internet use, but the statistically significant effect remains with the problematic smartphone use (OR: 1.029, 95% CI (1.003, 1.056), p < 0.01).
Hierarchical binary logistic regression models for normal weight status.
Dependent variable: normal weight status (coded as 0), abnormal weight status (underweight, overweight or obese) (coded as 1).
OR: odds ratio.
Hosmer–Lemeshow statistics indicates a poor fit if the significance value is less than 0.05.
p < 0.05.
Discussion
This study was conducted to determine whether problematic use of internet and smartphone affects dietary behaviors and abnormal weight status in young adults. The results showed that high levels of problematic internet and smartphone use had a negative effect on young adults’ dietary behaviors and consumption of food groups. In addition, after adjusting for potential factors, both levels of problematic internet and smartphone use had a negative effect on normal weight status according to hierarchical binary logistic regression results. To our knowledge, this is the first study to examine the association of problematic internet and smartphone use with dietary behaviors, including consumption of recommended food groups, and abnormal weight status in Turkish young adults.
Problematic use of internet and smartphone and unhealthy eating behaviors
With the development of technology, the use of the internet and smartphones has become a part of our lives. However, the overuse of these tools, which has the potential to become addictive, can negatively affect basic life behaviors such as eating. In a study examining the relationship between problematic internet use and dietary behavior in university students found that those with higher levels of the problematic use had higher rates of skipping breakfast, lunch and dinner (Kamran et al., 2018). Similarly, a study of Egyptian high school students found that those with problematic internet use were more likely to skip breakfast, prefer fast food and sugary drinks, and eat less fruits and vegetables as snacks (Kamal and Mosallem, 2013). A sample of Korean adolescents showed that those at high risk of problematic internet use consumed less fruit and milk than those who were not (Kim et al., 2010). The studies summarized above have some limitations compared to our study. These studies generally assessed snack food preferences, whereas our study assessed general dietary habits and consumption of main meals and recommended food groups according to the national dietary guidelines, rather than snacks. As a result of our study, the level of problematic internet use was found to be higher in those with irregular and unhealthy eating habits. However, when assessing the relationship between problematic internet use and dietary behavior in general, these results are in line with the findings of studies in the literature.
According to the literature review, the effects of problematic smartphone use on dietary behaviors have received less attention than internet. We consider that it is important and valuable to investigate the level of problematic smartphone use, as it is the most commonly used tool for accessing the internet in today’s technology, and its problematic use could affect eating behaviors. Based on the results of our study, the relationship between problematic smartphone use and dietary behaviors is similar to that of problematic internet use. There is no research in the literature that directly examines the effect of problematic smartphone use on dietary behaviors. Previous studies have generally analyzed the duration and frequency of smartphone use. A cross-sectional study conducted with 520 Korean university students found that those who used smartphones frequently (more than 6.4 hours per day) skipped meals more often, especially breakfast, had irregular eating habits, consumed more processed foods, and overeated (Lim et al., 2016). A similar cross-sectional study reported that university students who were high and potential risk smartphone users tended to skip meals, consume fewer nuts, and consume more fast food and alcohol (Park, 2017). Likewise, in another study with a large sample of 62,276 adolescents, higher consumption of fizzy drinks, sugary drinks, junk food, pasta and snacks was associated with higher smartphone use (Kim et al., 2021). Our findings are consistent with the results of studies in the literature. We can hypothesize that the problematic use of internet and smartphone may cause negative eating behaviors and our hypothesis is confirmed according to the results. Too many hours spent on the internet and smartphones may lead to a lack of awareness of hunger and the passage of time. There may also be less interest in healthy food, especially due to overexposure to unhealthy food advertising.
Problematic use of internet and smartphone and abnormal body weight
Abnormal weight status is often associated with overweight or obesity, but underweight is excluded from this definition. However, any condition that is not normal is abnormal. The evidence suggests that chronic disease, increased energy requirements and excess energy intake are among the factors that contribute to abnormal weight status (Hall et al., 2022; Wang et al., 2019). Previous studies have shown that eating disorders such as anorexia and bulimia nervosa are associated with underweight, whereas unhealthy dietary behaviors and excessive energy intake are generally associated with overweight and obesity (Mintziori et al., 2020; Varela et al., 2020). No studies have been identified in the literature to assess whether problematic smartphone use affects the risk of having abnormal weight. A systematic review and meta-analysis study concluded that an increase of 1 hour of internet use per day increased the risk of being overweight or obese by 8.0% (Aghasi et al., 2020). A case-control study conducted in our country (Türkiye) among adolescents found that problematic internet use score was higher in obese compared to non-obese (Eliacik et al., 2016). In a study, the highest problematic use of internet score was found in overweight and the lowest in underweight (Canan et al., 2014). The possible contribution of problematic use of internet and smartphone addiction to obesity can be explained by several aspects. Excessive internet and smartphone use requires problematic users to sit in front of a computer or smartphone for long periods of time every day, resulting in a lack of physical activity. This sedentary behavior can lead to obesity, whereas physical activity has been shown to reduce overweight and obesity (Zhu et al., 2019). Obese individuals may suffer from mobility and related social problems, and the internet may be their only way out. Individuals with problematic internet or smartphone use often have an irregular diets, eating snacks instead of regular meals and drinking non-nutritious beverages, which can lead to an increase in body weight (Loth et al., 2015). Problematic internet and smartphone use has also been shown to be associated with irregular sleep and depressive symptoms, and these conditions may contribute to weight gain (Hu et al., 2022).
Another accompanying finding of the present study was that a higher level of problematic use of internet and smartphone was also found in the underweight group compared to the normal group. This suggests that the relationship between problematic use and BMI may be U-shaped rather than linear, contrary to some studies in the literature (Gentile et al., 2021; Ying Ying et al., 2020). In a study, rates of problematic internet use in individuals with anorexia nervosa and bulimia nervosa, which are associated with underweight, were found to be 13.6% and 25.7%, respectively (Panea-Pizarro et al., 2020). A multi-faceted, systematic review and meta-analysis study reported that problematic internet use was associated with bulimic symptoms, restrictive eating, and drive for thinness (Ioannidis et al., 2021). Among 540 medical students, the risk of problematic internet use was positively associated with eating disorders and negatively associated with BMI (Kożybska et al., 2022). In this regard, we claimed that problematic use of internet and smartphone are not only associated with obesity, but may also be associated with underweight status, especially due to eating disorders and social media overuse related to body image and dissatisfaction (Tamarit et al., 2021). The association between problematic internet and smartphone use and underweight may be related to decreased daily dietary intake and/or appetite, and skipping meals (Park and Lee, 2017). This means that these problematic behaviors may have a negative impact on abnormal body weight, as observed in the results of our study.
Strength and limits
The strength of the present study is that the association of problematic smartphone use with dietary behaviors and abnormal weight status has been assessed, whereas previous studies have generally examined internet use. In addition, these situations were examined not only in terms of obesity, but abnormal body weight status with advanced statistical analyses, and it is argued that underweight should also be considered. Also, a multi-disciplinary approach was followed in the planning and conducting of the study. However, this study has some limitations. The main limitation of this study was the cross-sectional design, which hindered us to determine the causal relationship between the variables. The number and distribution of those in the BMI grouping is not equal, with more in the normal group than in the others, so it may not be enough to make generalizations. In addition, weight and height were self-reported. It is recommended that future studies include more detailed anthropometric measurements. Despite these limitations, this study provides important insights into the effects of internet and smartphone addiction on eating behaviors and abnormal body weight status in young adults.
Conclusion
Our study is one of the few studies in the literature to investigate the relationships between dietary behaviors, abnormal weight status, and problematic internet and smartphone use in a young adult population. The present study has shown that university students have considerable rates of unhealthy dietary behaviors, not consuming the recommended levels of healthy food groups, and that these conditions are associated with problematic use of internet and smartphone. It is suggested that treating internet and smartphone addiction may be a successful intervention approach for people with abnormal body weight, low consumption of healthy foods and unhealthy dietary behaviors. National strategies can be developed together with the stakeholders such as parents, health professionals and policy makers in order to control the overuse of the internet and smartphones, which are indispensable parts of our lives, in all age groups. A future large-scale prospective study using objective measurements is needed to clarify the causal relationship between these problems, dietary behaviors and abnormal weight status.
Supplemental Material
sj-pdf-1-hpq-10.1177_13591053241249542 – Supplemental material for Is problematic use of the Internet and smartphone predictor of unhealthy eating behaviors and abnormal body weight in Turkish young adults?
Supplemental material, sj-pdf-1-hpq-10.1177_13591053241249542 for Is problematic use of the Internet and smartphone predictor of unhealthy eating behaviors and abnormal body weight in Turkish young adults? by Hacı Ömer Yılmaz, Çağdaş Salih Meriç, Kenan Bülbül and Tuğba Türkkan in Journal of Health Psychology
Footnotes
Author contributions
HÖY: Conceptualization, Formal analysis, Writing – original draft, Writing – review and editing, Visualization, Supervision. ÇSM: Formal analysis, Writing – original draft, Writing – review and editing, Visualization. KB: Writing – original draft, Writing – review and editing. TT: Writing – original draft, Writing –review and editing.
Data sharing statement
Data will be made available on request by the corresponding author.
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
Ethics approval
This study was approved by of Gümüşhane University Scientific Research and Publication Ethics Committee (No: E-95674917-108.99-81066) and (Decision Number is 37).
Informed consent
All participants provided informed consent prior to their participation in this study.
References
Supplementary Material
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