The aim is to investigate the development of overweight and obesity from infancy to school age, and to evaluate an intervention to prevent further development of overweight and obesity among children.

A follow-up study will be conducted on 267 children and will allow comparison between children that developed overweight with the ones who did not. Subjects will be requited at 10 years of age from a previous project. These children have been studied when they were 6-18 months old and a follow-up was conducted at 4 years of age. Sixteen percent of the children were overweight at 4 years of age and retrospective data of e.g. food intake, blood lipids and anthropometric measurements exists. In the present follow-up data regarding food and physical activity habits, anthropometric measurements and blood samples of e.g. blood lipids, IGF1 will be collected.

An intervention study will be conducted on 80-120 overweight children that will be randomized into one intervention and one control group. An intervention during two years will encourage long term healthy habits regarding diet and physical activity through group meetings and supervision. Information about food habits will be collected through questionnaires, interviews and diaries. Measurement of physical activity and energy expenditure will be made with Sense Wear and double labeled water, and will be used to validate reported food intake. Further, anthropometric measurements and blood samples will be collected.