Researchers think they know why children aren’t getting enough sleep

For girls in particular, this is closely linked to quality of life.

Teenage girl in bed at night looking at a smartphone beside a digital clock.

Among upper secondary school students, only one in five gets enough sleep, the study shows.

(Stock photo: iStockphoto)

Walter Norman Wehus Walter Norman Wehus COMMUNICATIONS ADVISER

Presented by: Presented by: University of Agder

Published 27 June 2026 - 00:01

“Norway ranks among the worst countries in the world when it comes to children's sleep,” says Erik Grasaas at the University of Agder.

He and his colleagues analysed data from more than 45,000 Norwegian children in Years 5, 6, and 7. The responses come from Ungdata Junior, a nationwide survey of primary school pupils.

Children in this age group are recommended to sleep between 9 and 11 hours a night. . Only 53 per cent of the children in the study met this target.

The older they get, the less they sleep

Data from Ungdata shows that sleep duration declines steadily with age. In Year 5, around one-third of children do not get enough sleep. By Year 7, that figure has risen to nearly two-thirds.

“It’s important to establish healthy sleep habits early in life,” says Grasaas.

Portrait photo — Erik Grasaas conducts research on young people and their sleep habits. He believes this topic should be taught in schools.

The gap between boys and girls is widest in Year 7. At that age, 55 per cent of boys fail to get enough sleep, compared with 64 per cent of girls.

“There are significant physical and emotional changes taking place during these years. Girls often enter puberty earlier and tend to report higher levels of stress than boys. That may help explain some of the difference,” he says.

Grasaas notes that sleep duration continues to decline throughout adolescence. While a gradual reduction in sleep is a normal part of development, the trend is concerning. Among upper secondary school students, four in five sleep less than the recommended eight hours per night for their age group.

Strong link to quality of life

For girls, the link between sleep and quality of life is particularly clear. Those who get enough sleep are twice as likely to be satisfied with their own health compared with girls who don’t get enough sleep.

This link applies to all the areas the researchers measured: relationships with parents and friends, how they feel at home, and, not least, how they experience school life.

Children who get enough sleep are less bored at school, feel they receive more care from teachers, and are less likely to refuse to go to school.

“In the survey, the children describe how they perceive their own health. Even though it's their own assessment, it's a very good indicator of how the children are actually doing,” says Grasaas.

Screen time steals sleep

The survey shows that screen time and sleep are linked. Among girls who spend less than one hour on screens daily, 70 per cent get enough sleep.

Among those who spend six hours or more on screens, only one in four gets enough sleep.

“Physical needs are suppressed if you spend a lot of time on screens. Children completely forget that they are tired, hungry, thirsty, or need to use the restroom,” says Grasaas.

He explains that the blue light from screens also affects the body’s secretion of melatonin, the hormone that makes us sleepy.

“Screens affect us in so many ways that excessive use should really be discouraged for this age group,” says the researcher.

Should be part of the curriculum

Grasaas believes the findings should have direct consequences.

“Parents, teachers, and leaders of after-school activities all have a responsibility to ensure children get enough sleep. Sports clubs shouldn’t schedule games too late in the evening, for example. And why not teach children about the importance of sleep and good routines?” asks the researcher.

He wishes people talked more with children about what too little sleep actually does to the body.

“What are the signs that you’re not getting enough sleep? Is it hard to wake up in the morning? Do you get really irritable when you wake up? Do you feel like sleeping during the day?”

One final piece of advice from the researcher is to get children moving outdoors in fresh air and natural light.

“The more active children are, the better and longer they sleep. But don’t exercise intensely right before bedtime. That can make it harder to fall asleep,” he says.

Reference:

Grasaas et al. Prior-Night Sleep Duration and the Relationship to Quality of Life and Educational Context in Norwegian Pre-Adolescents, BMC Pediatrics, 2026. DOI: 10.1186/s12887-026-06830-6