The active leisure, in particular reading, and hours of sleep play an important role in health and body mass index (BMI) in children. The aim of this study is to analyze, by means of path analysis, how these variables interact in influencing children’s weight. Two hundred and ninety-one children took part in the study. Their BMI was calculated and they were interviewed. A path analysis indicates that spending more time on leisure-time reading facilitates the control of BMI in two ways. Firstly, it is associated a greater number of active leisure activities (r = .35 p < .001) and predicts more hours of sleep (β = .13 p < .05), which in turn predicts a lower BMI (β = –.15 p < .001). Furthermore, it has been observed that spending more time reading is associated with less time spent on sedentary leisure activities (r = –.17 p < .001). It would appear that in order to control overweight in children, it is necessary to foster a well-ordered lifestyle. Reading as the last activity of the day can make a significant contribution to this process.