This study analyzes peer effects on childhood obesity using data from the first two waves of the IDEFICS study, which applies several anthropometric and other measures of fatness to approximately 14,000 children aged two to nine participating in both waves in 16 regions of eight European countries. Peers are defined as same-sex children in the same school and age group. The results show that peer effects do exist in this European sample but that they differ among both regions and different fatness measures. Peer effects are larger in Spain, Italy, and Cyprus - the more collectivist regions in our sample - while waist circumference generally gives rise to larger peer effects than BMI. We also provide evidence that parental misperceptions of their own children's weight goes hand in hand With fatter peer groups, supporting the notion that in making such assessments, parents compare their children's weight with that of friends and schoolmates.
Objective: The aim of the present study was to investigate if context-specific measures of parental-reported physical activity and sedentary behaviour are associated with objectively measured physical activity and sedentary time in children. Design: Cross-sectional study. Setting: Seven European countries taking part in the IDEFICS (Identification and Prevention of Dietary-and Lifestyle-induced Health Effects in Children and Infants) study. Subjects: Data were analysed from 2-9-year-old children (n 5982) who provided both parental-reported and accelerometer-derived physical activity/sedentary behaviour measures. Parents reported their children's daily screen-time, weekly sports participation and daily outdoor playtime by means of the Outdoor Playtime Checklist (OPC) and Outdoor Playtime Recall Questions (OPRQ). Results: Sports participation, OPC-and OPRQ-derived outdoor play were positively associated with accelerometer-derived physical activity. Television viewing and computer use were positively associated with accelerometer-derived sedentary time. All parental-reported measures that were significantly associated with accelerometer outcomes explained only a minor part of the variance in accelerometer-derived physical activity or sedentary time. Conclusions: Parental-reported measures of physical activity and sedentary behaviour are not useful as a proxy for 2-9-year-old children's physical activity and sedentary time. Findings do not preclude the use of context-specific measures but imply that conclusions should be limited to the context-specific behaviours that are actually measured. Depending on the aim of the study, future research should carefully consider the choice of measurements, including the use of subjective or objective measures of the behaviour of interest or a combination of both.
Background: The prevalence of childhood obesity has increased during the past decades and is now considered an urgent public health problem. Although stabilizing trends in obesity prevalence have been identified in parts of Europe, preventive efforts in children are still needed. Using the socio-ecological approach as the underlying theoretical perspective, the IDEFICS project aimed to develop, implement and evaluate a community-based intervention for the prevention of childhood obesity in eight European countries. The aim of the present manuscript was to describe the content and developmental process of the IDEFICS intervention. Methods: The intervention mapping protocol (IMP) was used to develop the community-based intervention for the prevention of childhood obesity in 3 to 10 years old children. It is a theory-and evidence-based tool for the structured planning and development of health promotion programs that requires the completion of six different steps. These steps were elaborated by two coordinating centers and discussed with the other participating centers until agreement was reached. Focus group research was performed in all participating centers to provide an informed basis for intervention development. Results: The application of the IMP resulted in an overall intervention framework with ten intervention modules targeting environmental and personal factors through the family, the school and the community. The summary results of the focus group research were used to inform the development of the overall intervention. The cultural adaptation of the overall intervention was realised by using country specific focus group results. The need for cultural adaptation was considered during the entire process to improve program adoption and implementation. A plan was developed to evaluate program effectiveness and quality of implementation. Conclusions: The IDEFICS project developed a community-based intervention for the prevention of childhood obesity by using to the intervention mapping heuristic. The IDEFICS intervention consists of a general and standardized intervention framework that allows for cultural adaptation to make the intervention feasible and to enhance deliverability in all participating countries. The present manuscript demonstrates that the development of an intervention is a long process that needs to be done systematically. Time, human resources and finances need to be planned beforehand to make interventions evidence-based and culturally relevant.