Funding and Acknowledgements
The authors would like to thank all participants and funders of the original studies who contributed data to the ICAD. Pooling of the data was funded through a grant from the National Prevention Research Initiative (grant number G0701877; http://www.mrc.ac.uk/research/initiatives/national-prevention-research-initiative-npri/). The funding partners relevant to this award are the British Heart Foundation, Cancer Research UK, Department of Health, Diabetes UK, Economic and Social Research Council, Medical Research Council, Research and Development Office for the Northern Ireland Health and Social Services, Chief Scientist Office, Scottish Executive Health Department, The Stroke Association, Welsh Assembly Government, and World Cancer Research Fund. This work was additionally supported by the Medical Research Council (MC_UU_12015/3; MC_UU_12015/7), Bristol University, Loughborough University, and Norwegian School of Sport Sciences. The research was additionally supported by the Research Council of Norway (249932/F20). The UK Medical Research Council and the Wellcome Trust (grant reference 102215/2/13/2), as well as the University of Bristol, provide core support for the Avon Longitudinal Study of Parents and Children (ALSPAC). The authors also gratefully acknowledge the contribution of Professor Chris Riddoch, Professor Ken Judge and Dr Pippa Griew to the development of the ICAD. The ICAD Collaborators include: Prof. Lars B. Andersen, Department of Teacher Education and Sport, Western Norwegian University of Applied Sciences, Sogndal, Norway (Copenhagen School Child Intervention Study [CoSCIS]); Prof. Sigmund A. Anderssen, Norwegian School for Sport Science, Oslo, Norway (European Youth Heart Study [EYHS], Norway); Dr Andrew J. Atkin, School of Health Sciences, University of East Anglia, UK; Prof. Greet Cardon, Department of Movement and Sports Sciences, Ghent University, Belgium (Belgium Pre-School Study); Centers for Disease Control and Prevention (CDC), National Center for Health Statistics (NCHS), Hyattsville, MD, USA (National Health and Nutrition Examination Survey [NHANES]); Dr Rachel Davey, Centre for Research and Action in Public Health, University of Canberra, Australia (Children’s Health and Activity Monitoring for Schools [CHAMPS]); Prof. Ulf Ekelund, Norwegian School of Sport Sciences, Oslo, Norway, and MRC Epidemiology Unit, University of Cambridge, UK; Dr Dale W. Esliger, School of Sports, Exercise and Health Sciences, Loughborough University, Loughborough, UK; Dr Pedro Hallal, Postgraduate Program in Epidemiology, Federal University of Pelotas, Brazil (1993 Pelotas Birth Cohort); Dr Bjørge H. Hansen, Norwegian School of Sport Sciences, Oslo, Norway; Prof. Kathleen F. Janz, Department of Health and Human Physiology, Department of Epidemiology, University of Iowa, Iowa City, IA, US (Iowa Bone Development Study); Prof. Susi Kriemler, Epidemiology, Biostatistics and Prevention Institute, University of Zürich, Zürich, Switzerland (Kinder-Sportstudie [KISS]); Dr Niels Møller, University of Southern Denmark, Odense, Denmark (EYHS, Denmark); Dr Kate Northstone, School of Social and Community Medicine, University of Bristol, UK (ALSPAC); Dr A. Page, Centre for Exercise, Nutrition and Health Sciences, University of Bristol, UK (Personal and Environmental Associations with Children’s Health [PEACH]); Prof. Russel Pate, Department of Exercise Science, University of South Carolina, Columbia, US (Physical Activity in Pre-school Children [CHAMPS-US] and Project Trial of Activity for Adolescent Girls [Project TAAG]); Dr Jardena J. Puder, Service of Endocrinology, Diabetes and Metabolism, Lausanne, Switzerland (Ballabeina Study); Prof. John J. Reilly, Physical Activity for Health Group, School of Psychological Sciences and Health, University of Strathclyde, Glasgow, UK (Movement and Activity Glasgow Intervention in Children [MAGIC]); Prof. Jo Salmon, School of Exercise and Nutrition Sciences, Deakin University, Melbourne, VIC, Australia (Children Living in Active Neigbourhoods [CLAN]); Prof. Luis B. Sardinha, Exercise and Health Laboratory, Faculty of Human Movement, Universidade de Lisboa, Lisbon, Portugal (EYHS, Portugal); Dr Lauren B. Sherar, School of Sports, Exercise and Health Sciences, Loughborough University, Loughborough, UK; Dr Anna Timperio, Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne, VIC, Australia (Healthy Eating and Play Study [HEAPS]); Dr Esther M.F. van Sluijs, MRC Epidemiology Unit and Centre for Diet and Activity Research, University of Cambridge, Cambridge, UK (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people [SPEEDY]).
Conflict of interest
Bjørge H. Hansen, Sigmund A. Anderssen, Lars B. Andersen, Maria Hildebrand, Elin Kolle, Jostein Steene-Johannessen, Susi Kriemler, Angie S. Page, Jardena J. Puder, John J. Reilly, Luis B. Sardinha, Esther M.F. van Sluijs, Niels Wedderkopp, and Ulf Ekelund declare that they have no conflicts of interest.
All procedures performed in the original studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
All participants and/or their legal guardian provided informed consent and local ethics committees approved the study protocols. Prior to sharing data, data-sharing agreements were established between contributing studies and the MRC Epidemiology Unit, University of Cambridge, Cambridge, UK.
The specific data sets generated and analysed during the current study are not publicly available; however, a new data set including the same variables can be applied for through an individual project agreement with ICAD (http://www.mrc-epid.cam.ac.uk/research/studies/icad/).