The Effects of the Jump-In Whole-School Intervention on the Weight Development of Children in Amsterdam, the Netherlands.

Background: This study assessed the effects of the "Jump-in" whole-school intervention in Amsterdam, the Netherlands, on children's weight development by comparing children exposed to the intervention and controls from 3 other large Dutch cities. Jump-in is a comprehensive intervention that aims to stimulate healthy nutrition and physical activity in children at primary schools in Amsterdam. In addition, the relationship between the intervention's implementation degree and its effectiveness was studied.