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 per cent 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 per cent 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 per cent higher odds of reporting sleep disturbance than those who only ate fast food once a week, while the odds were 49 per cent 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 behaviours needs to be a priority of policies and planning," he said.
"Strategies need to be customised 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 behaviours are influenced by their familial environments."
The study was conducted in collaboration with Griffith University, Queensland University of Technology, Deakin University, and Active Healthy Kids Bangladesh.
The research is published in the journal EClinicalMedicine (DOI:10.1016/j.clnesp.2020.01.011).
