Childhood obesity is defined as one of the most serious health challenges of this century (WHO). From being a raising problem in western societies and US in particular, it has become a global challenge, often connected to social inequality. Children suffering from obesity are inclined at remaining obese as adults, facing the risk for developing non-communicable diseases such as diabetes and cardio vascular diseases at an early age. Obesity and its comorbidities are preventable, and the prevention of childhood obesity is therefore increasingly important. In Norway, the authorities have introduced a program for regular weight measurements among preschool and school children. This program has three main goals, 1) to conduct an early identification of children at risk of developing obesity, in order to offer services and treatment, 2) follow the development locally, regionally and nationally, and 3) increase the knowledge about reasons to growth deviations, and about what preventable measure, local and national, which are appropriate for different age groups. Currently there are no standardized guidelines, services or interventions following this weight measurement program. With an interdisciplinary and multi-methods approach, this project will study the practices of this weight measurement program in Norway. The objective is to contribute to the development of improved services for the involved actors. In particular the project will focus on (eHealth) cooperation and communication before, during and after the weight measurements and practices at school, and addresses the needs of children, next of kins, health personnel, teachers and other relevant actors. Further we will explore whether and where eHealth technology can facilitate improved practices and outcomes.