# Associations Between Body Mass Index, Movement Behaviors, Motor Skills, Inhibition and Visuospatial Working Memory in Preschool Children: A Cross-Sectional Study Based on WHO References

## TL;DR

In Tunisian preschool children, BMI is mainly linked to physical growth, not to movement behaviors, motor skills, or cognitive functions.

## Contribution

This study provides new insights into the limited associations between BMI and developmental domains in early childhood using WHO references.

## Key findings

- BMI is significantly associated with anthropometric variables like weight and height in preschool children.
- No significant associations were found between BMI and physical activity, motor skills, or executive functions.
- Sleep duration showed a small significant difference between underweight and overweight children.

## Abstract

What are the main findings?
In Tunisian preschool children aged 4–5 years, Body Mass Index (BMI) according to World Health Organization (WHO) references is primarily associated with anthropometric characteristics such as weight, height, and BMI-for-age z-score.Statistically significant associations were observed for age and sleep duration between certain BMI groups, but these differences have limited practical relevance.No statistically significant associations were observed between BMI and daily physical activity (PA), sedentary behavior (SB), screen time (ST), executive functions (inhibition, working memory), or gross and fine motor skills (functional mobility, postural steadiness, lower and upper body strength, dexterity).

In Tunisian preschool children aged 4–5 years, Body Mass Index (BMI) according to World Health Organization (WHO) references is primarily associated with anthropometric characteristics such as weight, height, and BMI-for-age z-score.

Statistically significant associations were observed for age and sleep duration between certain BMI groups, but these differences have limited practical relevance.

No statistically significant associations were observed between BMI and daily physical activity (PA), sedentary behavior (SB), screen time (ST), executive functions (inhibition, working memory), or gross and fine motor skills (functional mobility, postural steadiness, lower and upper body strength, dexterity).

What are the implications of the main findings?
The small sample size, particularly for the underweight group, limits statistical power, so these results should be interpreted with caution.Future studies should include larger and more balanced samples, longitudinal or intervention designs, and examine mediating and moderating factors to clarify the relationships between BMI, PA, and early childhood development.Early childhood remains a key window for universal interventions to promote healthy growth, PA, and cognitive-motor development, regardless of weight status.

The small sample size, particularly for the underweight group, limits statistical power, so these results should be interpreted with caution.

Future studies should include larger and more balanced samples, longitudinal or intervention designs, and examine mediating and moderating factors to clarify the relationships between BMI, PA, and early childhood development.

Early childhood remains a key window for universal interventions to promote healthy growth, PA, and cognitive-motor development, regardless of weight status.

Background: Early childhood represents a key stage for the development of movement behaviors (MB), motor skills (MS), and executive functions (EF). Body Mass Index (BMI), defined according to World Health Organization (WHO) references, may influence these domains early in life. In this context, this cross-sectional observational study aimed to examine the associations between BMI and 24-h MB, MS, and EF in Tunisian preschool children aged 4 to 5 years. Methods: This cross-sectional observational study included 112 Tunisian children aged 4 to 5 years (50 boys, 62 girls), recruited from kindergartens in urban and rural areas. Anthropometric measurements were used to calculate age-specific BMI z-scores and classify children into three BMI categories: below normal, normal, and above normal. Twenty-four-hour MB physical activity (PA), sedentary behavior (SB), and sleep were objectively assessed using accelerometry over five consecutive days. EF (inhibition and working memory) were assessed using standardized cognitive tests, gross MS were evaluated using the Supine Timed Up and Go test (functional mobility), One-Leg Standing Balance test (postural steadiness), Hand Grip Dynamometer (upper body strength), and Standing Long Jump (lower body strength), and fine MS were assessed using the 9-Hole Pegboard Test (dexterity). All tools are validated and standardized for children. Results: Significant differences between BMI categories were observed for anthropometric variables (p < 0.05). In contrast, no significant differences were found for 24-h MB, adherence to recommendations, EF, and MS (p > 0.05). Only Sleep duration showed a difference significantly between BMI < normal and BMI > normal (p = 0.022). Conclusions: In Tunisian preschool children, weight status is primarily associated with differences in physical growth, with no marked relationship to MB, EF, or MS. These findings highlight the importance of universal preventive interventions, particularly focusing on growth monitoring, starting in early childhood. These results should be interpreted with caution and highlight the need for further studies on larger populations to better understand the relationships between BMI, PA, and development in young children.