Eating too much junk food has been linked with poor sleep quality in teens, a University of Queensland-led study has found.
UQ School of Health and Rehabilitation Sciences researcher Associate Professor Asad Khan said frequent consumption of soft drinks and fast food was strongly associated with sleep disturbance in adolescents around the world.
“This is the first study to examine unhealthy diets and stress-related sleep disturbance on a global scale in high school students from 64 countries,” Dr. Khan said.
“Overall, 7.5 percent of adolescents reported stress-related sleep disturbance, which was more common among females than males.
“Sleep disturbance increased with more frequent consumption of carbonated soft drinks, that often contain caffeine, and/or fast foods, that are traditionally energy-dense and nutrient-poor.
“Teens who drank more than three soft drinks per day had 55 percent higher odds of reporting sleep disturbance than those who only drank one soft drink a day.
“Males who ate fast foods on more than four days per week had 55 percent higher odds of reporting sleep disturbance than those who only ate fast food once a week, while the odds were 49 percent higher in females.
“Frequent consumption of soft drinks more than three times a day, and fast foods more than four days per week, were significantly associated with sleep disturbance in all but low-income countries.”
Data was collected from the World Health Organization’s Global School-based Health Surveys between 2009 and 2016, which included 175,261 students aged 12 to 15 years from 64 low, middle, and high income countries across South East Asia, Africa, parts of South America and the Eastern Mediterranean.
“Teens in high-income countries had the highest association between frequent intake of soft drinks and sleep disturbance,” Dr. Khan said.
“Females in these countries showed the biggest connection between regularly eating fast foods and sleep problems.
“Adolescents in South-Asia showed a high connection between drinking soft drink and sleep disturbance, while those in the Western-Pacific region showed the greatest link between both soft drink and fast food consumption and sleep issues.”
Dr. Khan said the findings were of particular concern as poor quality sleep adversely impacted on adolescent wellbeing and cognitive development.
“The targeting of these unhealthy behaviors needs to be a priority of policies and planning,” he said.
“Strategies need to be customized and tailored across countries or regions to meet their local needs.
“As stress-related sleep disturbance was more common among girls than boys, girls should be a priority target group for associated interventions that could target stress management and sleep quality.
“Creating school environments to limit access to carbonated soft drinks and fast foods, and introducing a sugar tax to lessen the sales of soft drinks may be beneficial.
“Family can also be instrumental in promoting healthy eating as the adoption and maintenance of children’s dietary behaviors are influenced by their familial environments.”
Obesity in children and adolescents is a major public health problem not only in industrialized countries but also in some developing countries. About 15% of Iranian children are obese and overweight (Kelishadi, 2007). Obesity during adolescence is a predictor of obesity in adulthood (Craigie et al., 2009).
The recent epidemic of obesity in children and adolescents has occurred in parallel with the reduction in sleep duration (Dollman, Ridley, Olds, & Lowe, 2007; Iglowstein, Jenni, Molinari, & Largo, 2003; Knutson, 2010). Today, sleep duration in children and adolescents has decreased compared to a decade ago (Matricciani, Olds, & Petkov, 2012). Recently, global review studies have shown a relationship between sleep deprivation and obesity in children and adults (Cappuccio et al., 2008; Chen, Beydoun, & Wang, 2008; Patel & Hu, 2008).
In addition, sleep duration is associated with some cardiometabolic risk factors in children and adolescents (Guo et al., 2011). Most eating habits and dietary patterns are formed in childhood and adolescence, and will be consistent throughout the life. These habits are associated with long‐term health, especially with cardiovascular risk factors in adulthood (Anderson, 1991; Kaikkonen et al., 2013).
Snacks are important in providing energy and nutrients, as it is reported that snacks provide about 40% of the daily energy of Iranian students (Dadkhah et al., 2008). It is reported that short sleep is associated with an increase snacking and preferences of high‐energy foods (Chaput, 2014). Mechanism through which inadequate sleeping increases energy intake includes more time and opportunity for eating, psychological distress, more energy need to endure long awakening, and increased appetite hormones (Chaput, 2014).
Limited studies have focused on the relationship between sleep duration and dietary habits, which found different results. A cross‐sectional study by Westerlund showed that less sleep time is associated with increased consumption of high‐energy foods such as fast foods and sweet snacks (Westerlund, Ray, & Roos, 2009). A number of cross‐over clinical trials have shown that limiting sleep causes more tendency for adolescents to eat high‐energy foods such as sweets and desserts (Beebe et al., 2013; Simon, Field, Miller, DiFrancesco, & Beebe, 2015).
Cross‐sectional and review studies in adults (Dashti, Scheer, Jacques, Lamon‐Fava, & Ordovas, 2015; Stamatakis & Brownson, 2008) and cohort study in children and cross‐sectional studies in adolescents showed that reducing the duration of sleep is associated with lower intake of fruits and vegetables (Garaulet et al., 2011; Tatone‐Tokuda et al., 2012).
A cross‐sectional study on 11‐ to 13‐year‐old Chinese adolescents showed a relationship between sleep deprivation and increased snack consumption only in boys (Lu, Hou, Sun, Zhang, & Tao, 2014).
In a cross‐sectional study on 1,870 students in Massachusetts, it was shown that inadequate sleep duration of less than 10 hr was associated with more drinking of soda and fewer intakes of vegetables, after adjustment for confounders. However, there was no correlation between sleep duration and the consumption of fruits and juices (Franckle et al., 2015).
Considering the increasing prevalence of obesity in children and adolescents, also due to high consumption of high calorie and low nutritive snacks in Iranian children and adolescents (Damari, Riazi‐Isfahani, Hajian, & Rezazadeh, 2015), knowing the relationship between sleep duration and food habits is urgent, to plan and implement effective interventions to prevent obesity and overweight.
Therefore, this study aimed to investigate the relationship between sleep duration and snacking in a national sample of children and adolescents aged 6–18 years old.
The results of this study showed that low sleep duration compared to long sleep is significantly associated with increased odds of daily intake of salty snacks, soft drinks, fast foods, tea, and tea with sugar. In addition, low sleep duration in students is associated with lower odds of daily consumption of diet drinks, soft beer, fresh fruits, and dried fruits, fresh juices, packed juices, milk, yogurt, and coffee. However, there was no significant relationship between sleep duration and consumption of cake, cheese, and vegetables.
Results of studies which assessed the relationship between sleep duration and unhealthy eating habits in children and adolescents are consistent with the current study. Results from a recent meta‐analysis also supported that short sleep duration was specifically related to more consumption of soda, snacks, and fewer fruits in children and adolescents (Cordova, Barja, & Brockmann, 2018).
Chaput et al. in a multinational cross‐sectional study on 5,777 children aged 9–11 years showed that lower sleep duration and later bedtime are significantly associated with unhealthy food pattern (Chaput et al., 2015). A cross‐sectional study on 1,265 students aged 9–11 years in Finland showed that there is a relationship between inadequate sleep and unhealthy energy‐rich food patterns including the following: pizza, hamburger, hot dogs or meat pastry; crisps or popcorn; cookies; ice cream; sweets or chocolate; and coca cola or other soft drinks (Westerlund et al., 2009).
A cross‐sectional study on 3,311 European adolescents showed that frequency of eating junk foods such as pizza, hamburger, and pasta snack products is higher in people who have a short sleep duration (Garaulet et al., 2011). A cohort study (2012) in Canada showed that short sleep times are associated with increased consumption of meat and meat products/alternatives in boys and an increase in the consumption of soft drinks in girls (Tatone‐Tokuda et al., 2012).
A cohort study in Canada showed that short sleep duration is associated with increased consumption of meat and meat products/alternatives in boys and increased consumption of soft drinks in girls (Tatone‐Tokuda et al., 2012). Franckle et al. (2015) also showed that sleep duration less than 10 hr is associated with more drinking of soda. A prospective study in Denmark on children aged 8–11 years showed that lower sleep duration is associated with higher intake of sugar containing foods/beverages (Hjorth et al., 2014).
In an experimental study, sleep deprivation was associated with increased appetite for high calorie and high carbohydrate foods such as sweets, salty snacks (chips, salted nuts, pickles, and olives), and starchy foods (bread, pasta, cereal, and potatoes) (Spiegel, Tasali, Penev, & Van Cauter, 2004).
Some studies have also examined the relation between sleep duration and the amount of energy derived from carbohydrate, protein, and fat. Martinez et al. in a cross‐sectional study showed that longer sleep duration is associated with lower carbohydrate intake (Martinez et al., 2017).
Weiss et al. (2010) in a cross‐sectional study in adolescents showed that less sleep duration is associated with increased odds of consuming calories from fat (Weiss et al., 2010). An experimental study on 37 children aged 8–11 years showed that higher sleep duration in students was associated with an average of 134 kcal/day less and lower weight (Hart et al., 2013).
In addition, the findings of this study showed that short sleep duration in students is associated with lower odds of daily intake of fresh fruits, dried fruits, fresh fruit juice, milk, yogurt, and coffee. There are some similar studies in adults. A review study showed that short sleep duration is associated with fewer fruits and vegetables intake and consumption of low‐quality foods (Dashti et al., 2015).
A cross‐sectional study by Stamatakis and Brownson (2008) on 1,203 adults showed that short sleep has a significant relationship with obesity‐related behaviors, in particular with lower physical activity and reduced consumption of fruits and vegetables. A cross‐sectional study on 410 female students aged 18–28 years in Isfahan showed that overweight and obesity is more prevalent among those who sleep <6 hr per day. In addition, energy and carbohydrate intake were higher, while protein, fiber, fruits, whole grains, and beans intake were lower (Haghighatdoost, Karimi, Esmaillzadeh, & Azadbakht, 2012).
There are also some similar studies in children. A cohort study in Canada showed that short sleep duration in children was associated with lower consumption of fruits and vegetables in both genders and lower dairy consumption in girls (Tatone‐Tokuda et al., 2012). A cross‐sectional study on 3,311 European adolescents showed that shorter sleep duration is associated with fewer fruits and vegetables consumption (Garaulet et al., 2011).
While Westerlund et al. (2009) showed a relationship between short sleep duration and lower consumption of healthy foods such as fruits, vegetables, and nutrient‐dense foods only in girls, a recent cross‐sectional study on 1,870 students in Massachusetts showed that after adjustment for confounding factors, inadequate sleep duration of less than 10 hr was associated with lower consumption of vegetables. However, there was no relationship between sleep duration and consumption of fruit and juice drinks (Franckle et al., 2015).
In the present study, no relationship was found between sleep duration and vegetables intake. Similar results were shown in a study on Chinese adults (Tu et al., 2012).
However, a systematic review (2018) focusing on the pediatric population showed that low sleep duration was associated with fewer vegetables and fruits (Cordova et al., 2018).
A cross‐sectional study showed that sleeping less during school nights is associated with lower consumption of nutrient‐dense foods, such as fruits and vegetables (Westerlund et al., 2009).
The reasons for the inconsistent findings may be the difference in characteristics of participant, methods of dietary intakes assessment, and different cultural conditions.
It could be due to the nutritional culture of the people, so that consuming more vegetables with main meals is less affected by reduced sleep duration. In an experimental study, it was shown that sleep deprivation (in an obesity‐promoting environment) is accompanied by increased intake of calorie from snacks, but without any significant changes in calorie intakes from main meals (Nedeltcheva et al., 2009).
Sleep restriction may affect an individual’s food intake by altering circadian cycle and by altering the level of hunger and satiety hormones (leptin and ghrelin), as well as by altering blood glucose levels (Knutson, Spiegel, Penev, & Van Cauter, 2007; Magee, Huang, Iverson, & Caputi, 2010; Spiegel, Tasali, Leproult, & Van Cauter, 2009).
It seems that sleep deprivation results in increased food intake through increasing appetite‐stimulating hormone (ghrelin) and decreasing appetite‐suppressing hormone (leptin) (Spiegel et al., 2004; Zadeh & Begum, 2011). In addition, individuals with sleep deprivation have more time to eat (Chaput et al., 2010; Qin et al., 2003). On the other hand, short sleep may lead to disordered consumption of the main meals and increased intake of junk foods and unhealthy snacks (Dashti et al., 2015).
It seems that short sleep duration increases the prevalence of obesity through changing hormone levels and probably by increasing the exposure of children to certain environmental factors such as watching TV (Garaulet et al., 2011; Magee, Caputi, & Iverson, 2014). As a study in children and adolescents showed, most children and adolescents watch TV before bedtime and screen time before sleeping delays bedtime (Foley et al., 2013).
Chaput et al. in a multinational cross‐sectional study on 5,777 children aged 9–11 years showed that short sleep duration is associated with more sedentary behaviors. Similarly, later bedtimes are associated with an increase in sedentary behaviors and screen time (Chaput et al., 2015).
Sedentary behaviors (like watching TV) are also associated with unhealthy eating habits such as increased intake of high‐energy snacks and fast foods and increased energy intake and reduced consumption of fruits and vegetables in children and adolescents (Azizi‐Soleiman et al., 2016; Pearson & Biddle, 2011; Safiri et al., 2016).
So, it increases overweight and obesity. As a review study shows, there is a positive correlation between unhealthy food patterns and cardiometabolic risk factors in children and adolescents (Rocha, Milagres, Longo, Ribeiro, & Novaes, 2017).
Some factors make comparing the findings of various studies difficult, including method of dietary intakes assessment (food frequency questionnaire, 24‐hr food recall), different definitions of sleep deprivation, different age groups, differences in analysis method, and difference in adjusted confounding factors.
In addition, food habits vary in different societies and may be influenced by the specific factors of that community, including the cultural level and the customs and customs of the community, attitude, role of parents, environmental conditions, food variety, and the extent of food access, as well as the modeling of peers.
Some limitations are outlined. First, it was a cross‐sectional study and a causal inference cannot be established. Other limitations include the method of collecting lifestyle information (dietary habits, physical activity, sedentary behaviors, and sleep duration) which was based on a self‐administered questionnaire, and thus, recall bias is probable.
In addition, if food items were collected quantitatively, intakes were determined more precisely. Also, despite the adjustment for some confounding variables, there were no data on puberty status and household income. As a result, they may affect the outcome of the study. In addition, there may be unknown confounding factors that are not controlled in this study.
The age range of participants in the current study was 6–18 years old. A study showed that sleep duration was associated with age, and older children suffer from greater sleep deprivation (Hitze et al., 2009). Sleep duration in children and adolescents may also be affected by factors such as puberty, physiological changes, and psychology.
On the other hand, the extent of parental supervision on food consumption may be related to the age of student. So that children are more likely to be supervised by parents than adolescents. Adolescents have more freedom to spend their leisure time outside the home compared to children, and they may be influenced by their peers in choosing snacks.
Large sample size was one of the strengths of this study. Second, the WHO standard questionnaire was used in this study. In addition, a large number of possible confounding factors were controlled in this study. Finally, high‐quality data gathering was another strength of the present study.
reference link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7174214/
More information: Asaduzzaman Khan et al. Association of carbonated soft drink and fast food intake with stress-related sleep disturbance among adolescents: A global perspective from 64 countries, EClinicalMedicine (2020). DOI: 10.1016/j.eclinm.2020.100681