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The combination of going to bed after ten at night and, previously, having been exposed to screens for more than half an hour (tablet, mobile phone, computer, television...) is associated with a higher risk of obesity and less adherence to the diet. Mediterranean diet in the child population, according to a new study from the University of Barcelona. The work, published in the magazine Appetite, has also detected that a significant percentage of boys and girls, 27.5% of preschoolers and 35.2% of those of school age, spend more than half an hour in front of one of these screen devices before going to bed.
"We have observed that preschool children who have more nocturnal sleep habits and spend more time in front of screens before bed have a higher risk of developing overweight or obesity, compared to those who go to bed more early and do not look at screens before going to bed," explains María Fernanda Zerón-Rugerio, first author of the study, who is a professor at the Faculty of Research in Nutrition and Food Safety (INSA). The work has been directed by Professor Maria Izquierdo-Pullido, from the Faculty of Pharmacy and Food Sciences and the Torribera Food Campus, and an INSA researcher. Dr. Alicia Santamaria, from Laboratorios Ordesa, has also participated.
Poor sleep quality and less physical activity
Research has also found that the combination of these two components results in a shorter duration of nighttime sleep, which is also of poorer quality, in both preschoolers and schoolchildren. These variables are also associated with a delay in breakfast and dinner times, especially as children's age increases.
Likewise, school-age children who maintain this combination of unhealthy habits also experience greater social jet lag and do less physical activity. "This is common among people who go to bed late, as they have to adjust their wake-up time to fit school schedules, rather than sleep needs. Therefore, they end up sleeping less and accumulate a sleep deficit throughout the week, a situation that in previous studies is associated with an irritable mood, poor academic performance and daytime sleepiness," the researchers explain.
Only 11.7% of school-age children do not watch screens and go to bed early
The study was based on data collected through online surveys of 1,133 Spanish children, 545 of whom are between two and four years old and 588 between five and twelve years old. These questionnaires analyze sleep habits and the use of devices with screens, as well as other indicators, such as diet or body mass index.
Approximately half of the school-aged children surveyed spend between one and thirty minutes in front of a screen before bed (50.5% and 45.1% respectively), while 27.5% of preschoolers and 35 .2% of schoolchildren spend more than half an hour. In fact, the results reveal that only 14.2% of preschool-age boys and girls and 11.7% of school-age boys and girls do not watch screens and go to sleep early.
The researchers are also surprised by the sleep schedules of the study participants. "We have confirmed that boys and girls tend to go to bed around ten at night. If we take into account that it is recommended that they sleep between ten and twelve hours, it is evident that many Spanish children do not get enough sleep," they point out.
In this situation, the UB experts recommend "progressing bedtime and, before going to sleep, reducing exposure to screens as much as possible, which ideally needs to be avoided completely at least an hour before." These are indications that are supported by the guidelines of the American Pediatric Association.
For the UB researchers, in the case of the child population it is "fundamental" to address the prevention of obesity and the lifestyle factors that can be modified, in order to promote healthy growth and development. These factors include bedtime and screen time before bedtime. "These are aspects of modern lifestyle that have to do with unhealthy eating habits and less adherence to healthy eating patterns, such as the Mediterranean diet. These habits, if maintained in the long term, can lead to obesity," they conclude. .
