The aims of the present study were to investigate the proportion of Finnish preschool children complying with the individual (i.e., PA, ST, and sleep) and combined 24-h movement guidelines for the early years as well as the association between complying with the guidelines and anthropometry. In accordance with the results, one-fourth of the preschool children met all three guidelines. Furthermore, meeting guidelines for PA and sleep were associated with lower BMI and WC, while there was no significant association observed regarding ST.
The proportion of children meeting all three guidelines within the 24-h movement guidelines was the highest on weekdays and the lowest on weekend days. This can partly be explained by the somewhat low compliance with the ST guideline. The majority of children met the guideline for PA overall and on weekdays, but on weekend days the highest compliance rate was for the sleep guideline. It is possible that parents might not have the same structure and routines to activate their children at home on weekends than the ECEC’s personnel do on weekdays. However, the results highlight the need to increase compliance, especially with ST. In addition, there should be more efforts put on promoting PA, particularly on weekend days, and sleep on weekdays.
There are only three previous studies that have been examined compliance with the 24-h movement guidelines for the early years in preschool children: one in Canada [8], one in Australia [9], and one in Belgium [10]. Similar to our study, the Canadian and Australian studies also reported the highest compliance rates for the PA and sleep guidelines, while the ST guideline received the lowest rates [8, 9]. In the Belgian study, however, the highest compliance was found for sleep and ST, while it was the lowest for PA [10]. The somewhat different findings can be partly explained by the methodological differences. For instance, in assessing PA the use of a different type of accelerometer device (ActiGraph vs. Actical), the use of different amounts of axes in capturing children’s acceleration (triaxial vs. uniaxial), and the use of a different cut-points in defining PA (Butte vs. Pate vs. Evenson) [8,9,10] can all affect the detected PA. This may further influence the proportion of children meeting the PA guideline. In addition, there were differences in assessing ST and sleep duration (open-ended questions vs. ready-given response categories), which may have affected the results. Due to these differences in methodology and study designs, comparing results to previous studies needs to be done with caution.
To the best of our knowledge, this is the first study that examines the associations of compliance with the 24-h movement guidelines for the early years with anthropometry in European preschool children. In accordance with our results, meeting the guidelines separately for PA or sleep, or for both of them, was associated with lower WC, whereas meeting the guidelines for sleep, or both PA and sleep, was associated with lower BMI. The Canadian study previously reported no significant associations between compliance with the 24-h movement guidelines and BMI in preschoolers [8], yet the differences in study designs need to be kept in mind. However, our results are in line with a large 12-country study in 9–11-year-old children (N = 6128) that investigated associations of compliance with the 24-h movement guidelines with BMI [18]. Although their guidelines were slightly different to the ones in younger children, they found that meeting all three guidelines regarding PA, ST, and sleep was associated with lower BMI. Moreover, we found that meeting two or three guidelines instead of none or one was associated with lower BMI and WC. These findings support the theory that these three movement behaviors are co-dependent, and thus, there is a great need for interventions that attempt to promote compliance of more than one movement behavior at a time.
Our results showed that the associations of meeting the guidelines for PA and/or sleep appeared to be stronger with WC compared to BMI. As an elevated BMI has been suggested to indicate more “overweight” than “over fatness” [19], WC has been commonly used as a marker for central obesity [20]. Thus, the findings indicate that meeting the guidelines for PA and sleep may have a role in decreasing visceral adipose tissue, which in turn has been related to adverse metabolic health consequences [20]. However, although we used accurate measures of anthropometry, we were not able to address associations between compliance with 24-h movement guidelines and body composition, such as fat mass or fat-free mass. Thus, in future studies, the use of more detailed measurements of body composition should be considered.
We found no significant association between meeting the guideline for ST with BMI or WC. It is possible that the rather short time, ≤60 min/day, was not enough to show the difference. Although ST has been connected to adverse health consequences, such as depressive symptoms and a poorer quality of health in children [21], our finding is encouraging. The use of ST has also been considered a way to promote children’s digital technology skills as well as to enhance learning and creating competence in social interaction [22]. However, it is essential to further examine the associations between ST and different health outcomes, and to clarify, for instance, the role of ST duration in order to support children’s health.
Strengths and limitations
The strengths of the present study include a relatively large sample of children as well as comprehensive assessments of PA, ST, and sleep duration. We used triaxial accelerometers instead of uniaxial in order to take into account children’s intermittent patterns of movement [13]. In addition, we chose to use the same cut-points that have also been used in other recent European studies on preschool children, increasing the comparability between the studies [23, 24]. The use of daily ST and sleep diaries with open questions instead of ready-given response categories in assessing ST and sleep were chosen to increase representativeness of ST and sleep. Finally, the daily ST diary included all types of ST (i.e., TV viewing, watching DVDs or videos, using tablets or smartphones, and using computers or playing computer games) instead of restricting it only to TV viewing [21].
The study also has some limitations that need to be considered. Firstly, the cross-sectional study design limits the conclusion about causality between the observed associations. Secondly, the sleep diary was filled in by the parents, and therefore, we have no information about whether the children had a nap while in ECECs. Thus, it is possible that the actual amount of sleep per day was slightly longer, which could increase the proportion of children meeting the guideline for sleep. Thirdly, we did not include any dietary factors (children’s energy intake) as we aimed to provide results that were well comparable with those of Chaput et al. [8]. Finally, due to the relatively low participation rate, the sample may be somewhat selected with participants interested in healthy lifestyles. This may have led to higher compliance rates than in the general population.