Body mass index (BMI) versus socioeconomic factors and physical activity in early childhood.

Physical activity is vital for a child’s development and is influenced by their living environment and parental role models. This study examined the relationship between selected socioeconomic factors, children’s physical activity levels, and Body Mass Index (BMI). Data were collected from 9,333 children aged 6.5 to 9.5 years participating in the “Physical Education (PE) with University of Physical Education (abbreviation in Polish - AWF)” Programme (2021–2024). Information included anthropometric data of children and parents, physical activity levels, children’s leisure activities, and parents’ employment status. The data was collected using a questionnaire designed for the programme. Children with normal BMI were more active and more often engaged in organized (χ2 = 33.92; p < 0.001) and unorganized (χ2 = 4.08; p = 0.04) physical activities than obese peers. They spent less time on passive activities like watching TV (χ2 = 51.57; p < 0.001) or using a computer (χ2 = 88.18; p < 0.001). Overweight children preferred sedentary and low-intensity activities. Normal BMI correlated with parents’ higher education and employment (mothers: χ2 = 115.80; fathers: χ2 = 45.30; both p < 0.001) and living in larger cities (χ2 = 40.14; p < 0.001). Parental education and employment positively influence children’s BMI and activity levels. Normal BMI is associated with greater engagement in both structured and unstructured physical activity.