The objective of this study was to assess the influence of physical activity on body weight in preschool children. The 3∼6 year-old physically healthy 113 early childhood in one children day care house were selected for this study. Body weight, height and physical activity were measured. Measurement of physical activity was walking number by accelerometer (electronic motion sensor, manbogi) during day care house (for 6 hours). Other daily living behavior data for subjects were gathered by parent's questionaire.
Subjects with overweight for age were 35.4%, obesity with early childhood were 6.2%. Walking number for overweight subjects by accelerometer were less than other preschool children's that (P=0.013). Also, subjects with overweight were correlated with eating behavior, especially more left over of food and favorite food intake than normal weight subjects. Early childhood with overweight had more TV/video viewing time than standard weight subject's that.
But sleeping time, snack frequency, breakfast, dinner time were not correlated with body weight.
We suspect early childhood body weight is closely correlated with daily physical activity, eating behavior, and TV/Video viewing time. We recommend primary care physicians may be educate to parent with overweight preschool children about physical activity, eating behavior and daily living habits.

Keywords: Preschool children, Accelerometer, Physical activity