Original researchDevelopmental pathways of change in fitness and motor competence are related to overweight and obesity status at the end of primary school
Introduction
Addressing factors that affect the worldwide obesity epidemic remains a priority as the number of overweight and obese children is approximately 37% in the US1, and 21% in Europe2. Although researchers agree that multiple variables influence the development of childhood obesity, it is important to understand which variables are most amenable to change, particularly for their remediation. Unfortunately, the wealth of strategies and interventions aimed at promoting positive and sustained nutrition and physical activity has not alleviated the growing childhood obesity epidemic. While many genetic and biological determinants of obesity may interact along the lifecycle3, 4, little attention has been paid to understand developmental trajectories of other potentially important behavioral factors linked to body weight status over time.
Very recently, Gutin5 has proposed a mediation model for the development of obesity during childhood. He argued that promoting vigorous types of exercise (i.e. the types that are strongly linked to physical fitness improvement) during the growing years will promote early differentiation of stem cells into bone and muscle rather than fat cells, with the contrary being also true. It should be noted that evidence of this mechanism already exists with animal models and evidence for humans are beginning to emerge6. Similar developmental rationale for fitness behaviors, allied to motor competence (MC) and perceived motor competence, are described by Stodden and collaborators in a recently proposed model that also is linked to physical activity and weight status trajectories of children7. The model predicts that healthy weight trajectories will evolve through either a positive or negative spiral of engagement or disengagement, respectively, in various physical activity behaviors across childhood that are inherently linked to motor skill, physical fitness, and psychological (i.e., perceived competence) development.
This view has been supported by several recent studies that showed how the development of motor competence8, 9, 10 and physical fitness11, 12, 13 are important contributing factors to positive or negative weight status development across childhood. While these studies demonstrated inverse longitudinal relationships of fitness and motor competence with weight status, researchers adopted a traditional “one size fits all” approach to the problem with all children's data being analyzed to “fit” a generalized model. Another approach that would uniquely address potentially different developmental pathways, as hypothesized by the Stodden et al. (2008) model7, would be to examine if there are positive and negative trajectories of motor competence and fitness across time. These two opposing (i.e., positive vs. negative) developmental pathways are hypothesized to result in divergent motor competence, fitness and weight status trajectories across childhood, with children from the negative pathway group being more prone to become overweight and obese, and vice-versa. In addition, it is hypothesized that there are other indirect factors that play a role in the continued or lack of development in motor competence and health-related physical fitness (i.e., perceived physical competence, self-efficacy, choices of physical activities) that also will affect weight status trajectories7. Due to direct and indirect mechanisms linked to the development of gross motor competence and many health-related fitness constructs relationships among these variables may be recursive and synergistic in nature7, 14, 15. Therefore addressing the cumulative effect of these related, yet distinct behavioral traits on body weight status, specifically from a longitudinal perspective, is important to address. The purposes of this study were to determine if different developmental pathways of change (measured by the summative changes across time) in motor competence and health-related fitness occur across childhood, and to examine whether these different pathways are predictive of unhealthy weight status through late childhood (i.e., end of primary school). To this endeavor we proposed a novel methodological approach, which was to assess four year trajectories of fitness and motor competence defined by differing rates of change, rather than the more traditional approach of assessing change from baseline only with the entire sample12, 16.
Section snippets
Methods
This study included 472 Caucasian children (239 boys, 233 girls) longitudinally assessed on their health related physical fitness, motor competence, and growth, throughout the primary school years (yearly from 1st to 4th grade). A balanced sex (50.6% of boys) and urban/rural gradient (49%/51%) was promoted in the sample selection from 15 primary public schools at Viana do Castelo (northern Portugal). Exclusion criteria included having less than three valid assessment points, being motor or
Results
Boys and girls showed similar height, weight, and BMI over childhood years (p > 0.05 for all ages) (see descriptive values in supplementary material online).
For weight status, the overall percentage of children that were overweight or obese (OW + O) increased over childhood from 22.5% to 30.3%. On the final testing time (T4) 30.5% of boys, and 30.0% of girls were classified as overweight or obese. There were no differences between boys and girls (Fisher's Exact Test p = 0.921).
Individual pathways on
Discussion
The purpose of this study was to examine the predictions of Stodden and colleagues’7 model that hypothesized that children will demonstrate distinct and sometimes divergent developmental pathways of motor competence and health-related fitness across childhood leading to different weight status outcomes. Results of this study generally support this contention. Although lacking specific data on physical activity and perceived motor competence, it is reasonable to speculate that, according to the
Conclusion
In conclusion, we found that children‘s health-related fitness and motor competence development across childhood years can be represented by three developmental pathways or trajectories, and that these different developmental pathways relate to different probabilities in overweight or obese status. Children with a better (more rapid) increase in health-related fitness and motor competence along childhood are less prone to develop an overweight or obesity condition. This conclusion generally
Practical implications
- •
Not all children increase their health-related physical fitness and motor competence across childhood years.
- •
Increasing health-related fitness and motor competence during childhood can be protective for unhealthy weight development.
- •
Children that show better (more rapid) development in health-related fitness and motor competence are less prone to develop an overweight or obese condition.
- •
Children that do not improve or have just a very small improvement in their cardiorespiratory fitness during
Acknowledgments
We wish to acknowledge the supporting role of the Municipality of Viana do Castelo as a sponsor of this research.
We thank the children, their families, and all schools and teachers who gave their time to participate in this study.
References (30)
- et al.
Pediatric obesity: etiology and treatment
Pediatr Clin N Am
(2011) - et al.
Etiologies of obesity in children: nature and nurture
Pediatr Clin N Am
(2011) Changes in motor skill and fitness measures among children with high and low motor competence: a five-year longitudinal study
J Sci Med Sport
(2008)- et al.
Correlation between BMI and motor coordination in children
J Sci Med Sport
(2012) - et al.
Prevalence of overweight and obesity in the United States, 1999–2004
JAMA
(2006) - IASO. Prevalence of overweight and obesity in children by WHO Region [Web] London: International Association for the...
Diet vs exercise for the prevention of pediatric obesity: the role of exercise
Int J Obes
(2011)- et al.
Mechanical signals as a non-invasive means to influence mesenchymal stem cell fate, promoting bone and suppressing the fat phenotype
Bonekey Osteovision
(2009) - et al.
A developmental perspective on the role of motor skill competence in physical activity: an emergent relationship
Quest
(2008) - et al.
Motor coordination, physical activity and fitness as predictors of longitudinal change in adiposity during childhood
Eur J Sport Sci
(2012)