The risk of overweight in 6–8 year–old children who are active more than three hours a day and sedentary less than six hours a day is lower than among their physically more passive peers, according to new research from the University of Eastern Finland. Examples of sufficiently intensive physical activity include walking, cycling and active games. Published in the Liikunta ja Tiede journal of the Finnish Society of Sport Sciences, the findings constitute part of the Physical Activity and Nutrition in Children (PANIC) Study carried out in the University of Eastern Finland.

Overweight is increasingly common among children and adolescents. Despite this, research evidence on the associations of the amount and intensity of physical activity with overweight in children is surprisingly scarce. The study investigated the associations of objectively measured physical activity and sedentary time with age and gender standardised BMI and prevalence of overweight among 386 Finnish 6–8 year–old children. Physical activity and sedentary time were assessed using a combined heart rate and movement sensor. Various confounding factors including diet quality and parental and family background were controlled for in the analyses.

The study showed that children with less physical activity and more sedentary time had a higher BMI than their peers.

The intensity of physical activity is described using MET values, expressing the energy cost of physical activities. The study found that the minimum threshold for sufficient physical activity was 3.5 hours of any daily physical activity exceeding 2 METs. The threshold for sedentary time was less than 6 hours per day. Overweight and obesity was more common in children who were physically active less than 3.5 hours a day and sedentary more than 6 hours a day than in their peers. Examples of physical activity at the level of a minimum of 2 METs include walking, cycling, climbing, games involving running, several ball games, gymnastics and dance. Examples of sedentary time, on the other hand, include sitting on a couch, travelling by car and lying around.

“Children can reap the benefits of an active lifestyle that prevents the effects of overweight by playing games at varying degrees of intensity and by doing other things that keep them active. Exchanging sedentary behaviour such as screen time for more active games can help,” says Postdoctoral Researcher Eero Haapala, the first author of the article.

Promoting an active lifestyle can help prevent overweight already in childhood. Several recommendations on children’s physical activity also state that children need at least three hours of physical activity at varying degrees of intensity on a daily basis.