1. School of Sport, Exercise and Health SciencesLoughborough University Loughborough UK
2. Centre for Longitudinal StudiesUniversity College London (UCL) Institute of Education London UK
3. UKCRC Centre for Diet and Activity Research (CEDAR), MRC Epidemiology Unit, School of Clinical MedicineUniversity of Cambridge Cambridge UK
4. Department of Health, Behavior and Society, Johns Hopkins Bloomberg School of Public HealthJohns Hopkins University Baltimore Maryland USA