New research project will investigate the effect of sleep extension on body weight, metabolism and learning ability in children

Research has shown that inadequate sleep increases risk of obesity in both children and adults, and that loss of just a few hours of sleep can have negative effects on cognitive functions such as attention and memory – and thus potentially on the ability to learn and perform in school. 

Can extra sleep improve body weight and learning ability in children with overweight?

In a newly established collaboration, the Department of Nutrition, Exercise and Sports at the University of Copenhagen, and the Danish Centre for Sleep Disorders at Rigshospitalet, together with several other national and international partners, have launched MORE2SLEEP; a study that explores how extra sleep affects overweight children's ability to regulate body weight and learning ability. Head of MORE2SLEEP, Professor Faidon Magkos from the Department of Nutrition, Exercise and Sports at the University of Copenhagen, explains:

"There is a significant body of evidence linking too little sleep with overweight and obesity. This is particularly true among children and young people. In this age group, short sleep has also been associated with lower academic performance in school. However, we know little about the mechanisms behind these associations. More importantly, we lack knowledge about what can be done to reverse these negative effects,” says Faidon Magkos. He continues:

“Limited available evidence from experimental studies in adults suggests that sleep extension improves eating behaviors and body weight homeostasis. We will test this hypothesis in children. With the team of researchers we have gathered, and with the research project we have designed, MORE2SLEEP has the potential to become a milestone for understanding the mechanisms between sleep duration, body weight, metabolism and learning."

Why is sleep so important?

Professor Poul Jørgen Jennum, chief physician, DMSc, and head of the Danish Centre for Sleep Medicine at Rigshospitalet, is also part of the study. He explains that the quality of the few existing studies is limited due to few participants and short intervention periods, thereby preventing drawing robust conclusions. In MORE2SLEEP the children should sleep an additional 45-60 minutes every night for 12 weeks – with a follow-up for 6 months – which will enable the researchers to follow the effects over an extended period of time and thereby gain much greater knowledge than previously possible.

“In fact, we do not know what happens when you increase the amount of sleep in children who are overweight and sleep too little. That is why we will now be following 300 children aged 6 – 9-years. This can provide us with crucial new knowledge in relation to how sleep affects children's regulation of metabolism, the balance between hunger and appetite, memory functions and much more. With our study, we will increase our knowledge of what children's sleep means for their development, and then be able to give health advice to parents and decision makers," says Poul Jørgen Jennum.

Sleep is important for learning ability

Associate Professor Jesper Lundbye-Jensen from the Department of Nutrition, Exercise and Sports at the University of Copenhagen is in charge of the part of the study that relates to cognitive function, memory and learning. He explains that there are well-documented correlations between sleep, cognitive function and learning:

"We know that sleep is of great importance for cognitive function and for memory, and if we lose sleep, this can negatively affect learning ability. Among other things, this is because an important function of sleep is the consolidation of memory. But we do not know if increasing sleep duration in children who sleep too little provides significant benefits. This is why this project is so important – because we are investigating the effects on cognitive function and learning, but also the underlying changes in the brain," says Jesper Lundbye-Jensen.

The basis for treatment strategies and sleep recommendations

According to Professor Arne Astrup, MD, DMSc, and Senior Vice President and leading Obesity and Nutritional Sciences in the Novo Nordisk Foundation, MORE2SLEEP can become a reference point for future studies on sleep in relationship to obesity, neurophysiology, and cognitive function in children:

"With the grant for MORE2SLEEP, the Novo Nordisk Foundation wants to give the researchers the opportunity to produce novel knowledge about the role of sleep for body weight and mental performance. The ambition is that knowledge from the project can lead to new and better sleep recommendations for parents, health policy makers, and others who are responsible for the health of young children. In this way, the project could have a positive effect on how children sleep, what they eat, on their weight, and on their learning abilities. These beneficial effects can follow them for the rest of their lives,” says Arne Astrup.