Abstract

Objective

Poor sleep quality is common among young adults, and there are many modifiable factors associated with it. The aim of this study is to evaluate the relationship between sleep quality, obesity, the MEDFICTS (meats, eggs, dairy, fried foods, in baked goods, convenience foods, table fats, and snacks) diet, and social media addiction in young adults.

Materials and Methods

This descriptive cross-sectional study was conducted with 200 young adults aged 18-25. The study data were collected using the Pittsburgh Sleep Quality Index (PSQI), the MEDFICTS diet assessment questionnaire, and the social media addiction scale (SMAS). A PSQI score of >5 was interpreted as poor sleep quality, while a score of ≤5 was considered good sleep quality.

Results

Seventy percent of the young adults participating in the study had poor sleep quality. According to the results of simple linear regression analysis, body mass index (β=0.095, p=0.031), the MEDFICTS diet score (β=0.076, p=0.000), and the SMAS score (β=0.076, p=0.000) were found to have a statistically significant and positive effect on the PSQI score. In the results of multiple linear regression analysis, the MEDFICTS diet score (β=0.070, p=0.000) and SMAS score (β=0.053, p=0.000) were also observed to have a statistically significant and positive effect on the PSQI score.

Conclusion

This study demonstrates that obesity, the MEDFICTS diet, and social media addiction are associated with poor sleep quality. Considering the close relationship between sleep and overall health, public health initiatives are needed to reduce obesity and social media use among young adults and to promote healthy eating habits.

Introduction

Sleep quality is closely related to human health.¹ In young adults, sleep quality affects growth, development, academic achievement, cognitive development, a strong immune system, metabolic diseases, and mental health.^{2, 3} However, there is a global conceptual confusion about how exactly good sleep quality should be defined.⁴ While sleep quality is related to sleep duration, it is a more complex phenomenon. Good sleep quality refers to satisfaction with sleep efficiency, sleep latency, sleep duration and wakefulness after sleep onset.⁴ Physiological, psychological, environmental, familial, and social factors form the basis of good sleep quality.⁴ The best assessment of sleep quality includes both subjective and objective measurements.^{5, 6}

Good sleep quality allows individuals to feel rested and exhibit normal reflexes during the day, while poor sleep quality leads to issues such as fatigue, irritability, and dysfunction.⁴ A study evaluating the bidirectional relationship between sleep quality and multimorbidity in Chinese adults found that individuals with poor sleep quality were more likely to develop multimorbidity in the future. Additionally, individuals with multimorbidity exhibited worse sleep quality.⁷ Similar studies report that sleeping more or less than necessary increases the risk of developing chronic diseases such as stroke, cancer, obesity, depression and diabetes.^{8, 9}

Sleep disorders among young adults are a global public health issue.¹⁰ While the outcomes of sleep quality are well-known, the factors affecting good sleep quality are highly diverse and complex. It is recognized that sleep quality has a bidirectional cause-and-effect relationship with obesity.^{11, 12} Additionally, some authors have reported that sleep quality is associated with certain dietary patterns and nutrient profiles.^{13, 14} The silent pandemic of recent times, social media addiction, is also closely linked to sleep quality,¹⁵ though further research on this topic is necessary. This study aims to evaluate the relationship between sleep quality, obesity, the MEDFICTS (meats, eggs, dairy, fried foods, in baked goods, convenience foods, table fats, and snacks) diet, and social media addiction in young adults.

Materials and Methods

This study is a descriptive cross-sectional study conducted between December 1-31, 2024. The study population and sample consisted of 200 young adults aged 18-25, studying in the Department of Nutrition and Dietetics at Ağrı İbrahim Çeçen University Faculty of Health Sciences in Ağrı, Türkiye. Participants were included if they did not have a chronic or metabolic disease diagnosed by a physician, were not using medication, and met the age criteria. All questions regarding the participants were asked directly by the researcher and recorded on questionnaire forms using a face-to-face interview technique. Written and verbal consent was obtained from all participants who agreed to participate in the study. In addition, the ethical approval of the study was approved by Ağrı İbrahim Çeçen University Scientific Research Ethics Committee (decision number: 428, date: 28.11.2024).

Data Collection Tools

The data for the study were collected using the Pittsburgh Sleep Quality Index (PSQI), the MEDFICTS diet assessment questionnaire, and the social media addiction scale (SMAS), in addition to a sociodemographic information questionnaire prepared by the researcher based on a relevant literature review.

Sociodemographic Information Questionnaire

The questionnaire included questions about participants’ age, gender, body weight, height, marital status, place of residence, employment status, income level, smoking habits, alcohol consumption, and social media accounts used. Body mass index (BMI) (BMI = kg/m²) values were calculated from the participants’ weight and height measurements and classified according to WHO criteria: <18.5 kg/m² as “Underweight”, 18.5-24.9 kg/m² as “normal weight”, 25.0-29.9 kg/m² as “overweight,” and ≥30 kg/m² as “obese”.¹⁶

Pittsburgh Sleep Quality Index

The PSQI, used to assess participants’ sleep quality, was developed by Buysse et al.⁶ and its validity and reliability for the Turkish population were established by Yücel Ağargün et al.¹⁷ The index consists of seven components, each scored between 0 and 3. The scores of all components are summed to calculate the sleep quality index. The PSQI yields a total score ranging from 0 to 21, with higher scores indicating poorer sleep quality. In general, a score >5 is interpreted as poor sleep quality, while a score ≤5 is considered good sleep quality.^{6, 17}

MEDFICTS Diet Assessment Questionnaire

The MEDFICTS diet assessment, developed by Srinath et al.¹⁸ to evaluate individuals’ intake of total fat, saturated fat, and cholesterol, was validated and adapted for the Turkish population by Mermer et al.¹⁹ The MEDFICTS diet questionnaire comprises eight main food categories: meats, eggs, dairy, fried foods, in baked goods, convenience foods, table fats, and snacks. The total score is determined by calculating the frequency and amount of consumption of foods in each category as specified in the guideline. An increase in the total score is interpreted as an increase in the intake of fat, saturated fat, and cholesterol in the individual’s diet.^{18, 19}

Social Media Addiction Scale

The SMAS was developed by Şahin and Yağcı²⁰ to evaluate social media addiction among adults in the Turkish population. The scale consists of 20 items in a five-point Likert format, with response options to be marked as “not suitable for me at all (1 point)”, “not suitable for me (2 point)”, “undecided (3 point)”, “suitable for me (4 point)”, and “completely suitable for me (5 point)”. The scale does not have a cut-off point; instead, higher scores indicate that the individual perceives themselves as being “addicted to social media”. Additionally, items 5 and 11 on the scale are reverse scored.²⁰

Statistical Analysis

The collected data were analyzed using SPSS for Windows 25.0. Descriptive statistical methods were used in data evaluation. The normality of the data distribution was examined using Q-Q plot analysis, and normal distribution was defined as skewness and kurtosis values within the range of ±3. To investigate relationships among numerical variables and to examine the effects of independent variables on the dependent variable, simple and multiple linear regression analyses were applied. A p-value of <0.05 was considered statistically significant.

Results

The distribution of the sociodemographic characteristics of the participants is presented in Table 1. The participants were aged between 18-25 years, with a mean age of 21.51±1.58 years. Among the young adults, 80.5% were female, and 19.5% were male. When the distribution of the participants according to BMI classification was analyzed, it was seen that 11.0% were underweight, 73.0% were normal, 13.0% were overweight, and 3.0% were obese. 100.0% of the participants were single and the majority of them lived in student dormitories (76.0%). Most of the participants stated that they were not employed (92.0%), had a moderate income (70.0%), did not smoke (81.0%) and did not consume alcohol (89.0%). The five most commonly used social media platforms among the participants, all of whom owned smartphones, were WhatsApp (99.5%), Youtube (90.0%), Instagram (89.0%), Snapchat (60.5%) and Twitter (44.0%).

The distribution of participants based on their PSQI scores is presented in Table 2. According to the results, only 30% of the young adults had good sleep quality, while the majority, 70%, had poor sleep quality.

The results of the simple linear regression analysis conducted to estimate the predictive value of BMI, MEDFICTS diet, and social media addiction scores using PSQI as the dependent variable are presented in Table 3. The model established to investigate the effect of BMI on PSQI was found to be statistically significant (F=4.728, p=0.031). BMI had a statistically significant and positive effect on PSQI (β=0.095, p=0.031). The model explained 2.3% of the variance (R²=0.023). Additionally, there was no autocorrelation problem in the model, as the Durbin-Watson (DW) value was between 1.5 and 2.5 (DW=1.791). The model established to investigate the effect of MEDFICTS diet values on PSQI was found to be statistically significant (F=286.933, p=0.000). The MEDFICTS diet value had a statistically significant and positive effect on PSQI (β=0.076, p=0.000). The model explained 59.2% of the variance (R²=0.592). Additionally, there was no autocorrelation problem in the model, as the DW value was between 1.5 and 2.5 (DW=1.781). The model established to examine the effect of social media addiction scores on PSQI was statistically significant (F=52.978, p=0.000). Social media addiction scores had a statistically significant and positive effect on PSQI (β=0.076, p=0.000). The model explained 21.1% of the variance (R²=0.211). Additionally, there was no autocorrelation problem in the model, as the DW value fell between 1.5 and 2.5 (DW=2.039).

The results of the multiple linear regression analysis, in which PSQI was used as the dependent variable to estimate the predictive value of BMI, MEDFICTS diet, and social media addiction scores, are presented in Table 4. The model established to investigate the effect of BMI, MEDFICTS diet, and social media addiction scores on PSQI was found to be statistically significant (F=153.760, p=0.000). It was observed that MEDFICTS diet (β=0.070, p=0.000) and social media addiction (β=0.053, p=0.000) scores had a statistically significant and positive effect on PSQI. The model explained 70.2% of the variance (R²=0.702). There was no autocorrelation problem in the model, as the DW value was between 1.5 and 2.5 (DW=1.890).

Discussion

The relationship between good sleep quality and health is important across all age groups, from childhood to old age.^{21, 22} However, it is particularly significant for young adults attending university, as sleep quality not only supports their overall health²³ but may also contribute to their academic success, although there is no complete consensus in the literature.^{24, 25} Therefore, it is crucial to understand and control modifiable risk factors that impact sleep quality. This study evaluates the relationship between sleep quality and well-known factors such as high BMI, nutrition (fat and cholesterol intake), and social media addiction.

Poor sleep quality is common among young people, and it was observed that 70% of the young participants in this study had poor sleep quality (Table 2). In a study conducted with young individuals aged 18-29 in Jordan, 62.66% of the participants reported poor sleep quality.²⁶ Similarly, in a study evaluating 462 women aged 23, nearly half of the participants reported poor sleep quality.²⁷ A study conducted in Saudi Arabia reported that 72.5% of the general population experienced poor sleep quality, with the highest prevalence observed among young adults aged 18-28 (81.7%).²⁸ Furthermore, the recent Coronavirus Disease 2019 pandemic is also known to be associated with poor sleep quality.²⁹ Young adulthood, often coinciding with university years, is a period marked by high levels of future anxiety and social pressure. During this time, the time spent on social media and unhealthy food choices in social settings may directly or indirectly impact sleep quality.

Although BMI values did not show a statistically significant effect on PSQI in the results of the multiple linear regression analysis, the simple linear regression analysis results indicated a statistically significant and positive effect (Table 3 and Table 4). This suggests that young individuals with higher BMI tend to have poorer sleep quality. There is a bidirectional relationship between obesity and sleep quality.¹¹ Obesity can impair sleep quality by increasing the risk of sleep disorders.³⁰ Researchers who consider obesity as a factor that can disrupt sleep quality often focus on obstructive sleep apnea (OSA).³¹ OSA is a type of sleep disorder in which respiratory functions suddenly stop during sleep. OSA, which is particularly observed in individuals with high BMI, narrows the airway by reducing the activity of upper airway muscles due to excessive fat accumulation around the neck, leading to sleep deprivation with hypoxic attacks.³² Another critical point in OSA is the reduction in serum lipoprotein lipase (LPL) concentrations.³³ The decrease in LPL, which hydrolyzes fatty acids from circulating chylomicrons and VLDL, is a well-defined mechanism for hyperlipidemia associated with OSA.³⁴ This represents the adverse effect of obesity on sleep quality. Researchers have also presented evidence that poor sleep can lead to obesity and negatively affect weight loss. A study involving 2,100 young adult university students demonstrated that poor sleep quality is associated with obesity status.³⁵ A study involving 14,471 participants revealed that individuals with poor sleep quality have a significantly higher likelihood of being obese compared to those with good sleep quality.³⁶ In a similar study, it was reported that obesity rates were significantly higher in adults who reported an average of less than 7 hours of night sleep per day.³⁷ This situation can be linked to circadian rhythm disruption in individuals with poor sleep quality, an increase in the hunger-regulating hormone ghrelin, and a decrease in leptin levels, leading to increased consumption of high-fat and high-carbohydrate foods, thereby causing obesity.³⁸ Excessive food intake associated with insufficient sleep can be considered a mechanism that increases obesity risk. All these factors may turn obesity into a vicious cycle in individuals with poor sleep quality.

Both simple and multiple linear regression analysis results revealed that the MEDFICTS diet score had a statistically significant and positive effect on PSQI (Tables 3 and Table 4). This indicates that young individuals with higher MEDFICTS diet scores tend to have poorer sleep quality. The MEDFICTS diet assessment questionnaire evaluates individuals’ total fat, saturated fat, and cholesterol intake.^{18, 19} This study is the first in the literature to evaluate the relationship between the MEDFICTS diet and sleep quality. A randomized controlled study assessing the effects of specific dietary patterns on sleep quality demonstrated that adults with high saturated fat intake experienced slower wave sleep and longer sleep latency.³⁹ The same study reported that higher sugar intake increased nighttime awakenings in participants, while higher fiber intake was associated with fewer wake-up problems during sleep.³⁹ This study provides significant insights into the potential impact of low-quality carbohydrates (low fiber, high starch) or high saturated fat intake on sleep quality.³⁹ In a study evaluating the relationship between adherence to the Mediterranean diet—characterized by the consumption of whole grains, fruits, vegetables, legumes, nuts, fish, and olive oil, while limiting red meat and high-saturated-fat dairy products—and sleep quality, it was reported that better adherence to the Mediterranean diet improved sleep quality.¹³ In a recent study, it was determined that an increase in the cholesterol/saturated fat index was associated with a higher likelihood of experiencing sleep problems.⁴⁰ However, there are also authors in the literature who argue that food or fat intake is not related to sleep quality. In their study, Oliveira and Marques-Vidal⁴¹ (2023) reported no significant relationship between various foods and nutrients and sleep quality, and that fat intake did not impair sleep quality. Similarly, a review evaluating 4,155 publications also concluded that no specific diet had a marked effect on sleep quality.⁴² Although the underlying mechanisms of how high-fat diets affect sleep quality have not yet been fully understood, studies generally focus on the potential of high-fat diets to cause weight gain, which may reduce the sensitivity of orexin neuropeptides responsible for regulating the body’s sleep schedule, or disrupt the dopaminergic system, thereby impairing sleep quality.^{43, 44}

Both simple and multiple linear regression analysis results showed that social media addiction had a statistically significant and positive effect on PSQI (Table 3 and Table 4). This indicates that young adults who are more addicted to social media tend to have poorer sleep quality. Social media addiction is progressing as a silent pandemic among young adults. Although social media addiction is not officially recognized in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders by the American Psychiatric Association,⁴⁵ it can be defined as excessive preoccupation with social media, acting with an uncontrollable urge to access and use social media, and spending so much time on social media that other important aspects of life are adversely affected. A study conducted among Chinese young adults aged 18-27 reported that social media addiction not only led to poor sleep quality but also resulted in a decline in executive functions.⁴⁶ Another study evaluating Chinese undergraduate students found that more than half of those who used social media, particularly those spending 0.5-2 hours on social media before bedtime, experienced poorer sleep quality.⁴⁷ These findings are significant for young adults, as social media usage has been shown to impair the ability to fall and stay asleep by increasing cognitive and emotional stimulation, thereby negatively affecting sleep quality.^{48, 49} Additionally, excessive emotional investment in social media and frequent social media use can heighten pre-sleep cognitive arousal, leading to poor sleep outcomes.⁵⁰ All these findings provide important clues that social media use can disrupt sleep quality.

Although limited in number, there are also studies in the literature that evaluate the combined relationship of nutrition and social media addiction with sleep quality. A study conducted among university students demonstrated that as digital addiction increased, there was a parallel rise in nighttime eating and consumption of processed foods, which negatively affected both sleep duration and quality.⁵¹ In a similar study conducted among Chinese university students, a bidirectional relationship was reported between internet addiction and unhealthy dietary habits, with both factors directly influencing insomnia.⁵² These findings, which are consistent with the current study, suggest that increasing social media addiction—particularly screen exposure late at night—may trigger late-night snacking behaviors. This may explain the increase in unhealthy eating habits, as assessed by MEDFICTS scores, and the negative impact on sleep quality.

Study Limitations

The main limitation of this study is the relatively small sample size and the limited age range of the participants. Additionally, other confounding factors that could influence sleep quality, such as dietary intake records, physical activity levels, the average time spent on social media daily, the specific hours of day when participants are more active on social media, and factors like stress, were not assessed. This could also be regarded as another limitation of the study. However, considering the lack of studies in the literature that evaluate the relationship between MEDFICT diet and sleep quality, and the limited number of studies on the relationship between social media addiction and sleep quality in young adults, this study may provide a valuable contribution to the literature.

Conclusion

The young adulthood period is a time when significant steps are taken for later stages of life. During this period, especially for young adults studying at university, maintaining good sleep quality is associated with living a healthy life. Seventy percent of the young participants in this study reported poor sleep quality. This can lead to chronic diseases in later years or decrease the quality of life. The findings of this study indicate that young people’s sleep quality is closely related to BMI, MEDFICTS diet, and social media addiction. Social media addiction is particularly prevalent among young people. The foods often recommended on social media platforms are unfortunately low in nutritional value and high in simple carbohydrates and fats, typically fast food. Especially among young people who stay awake late into the night, exposure to advertisements for these foods on social media platforms and subsequent consumption can lead to obesity. This, in turn, can create a vicious cycle that negatively affects sleep quality.

In conclusion, public health interventions and policies should be developed to promote good sleep quality in young adults by ensuring weight control, encouraging healthy eating habits, and promoting moderate social media usage. Furthermore, larger-scale longitudinal studies are needed to fully understand the factors that affect sleep quality in young adults.