The parallel epidemics of childhood asthma and obesity over the past few decades have spurred research into obesity as a risk factor for asthma. However, little is known regarding the role of asthma in obesity incidence. We examined whether early-onset asthma and related phenotypes are associated with the risk of developing obesity in childhood.This study includes 21 130 children born from 1990 to 2008 in Denmark, France, Germany, Greece, Italy, The Netherlands, Spain, Sweden and the UK. We followed non-obese children at 3-4 years of age for incident obesity up to 8 years of age. Physician-diagnosed asthma, wheezing and allergic rhinitis were assessed up to 3-4 years of age.Children with physician-diagnosed asthma had a higher risk for incident obesity than those without asthma (adjusted hazard ratio (aHR) 1.66, 95% CI 1.18-2.33). Children with active asthma (wheeze in the last 12 months and physician-diagnosed asthma) exhibited a higher risk for obesity (aHR 1.98, 95% CI 1.31-3.00) than those without wheeze and asthma. Persistent wheezing was associated with increased risk for incident obesity compared to never wheezers (aHR 1.51, 95% CI 1.08-2.09).Early-onset asthma and wheezing may contribute to an increased risk of developing obesity in later childhood.

This work was partially supported by the Southern California Environmental Health Sciences Center (grant # P30ES007048) funded by the National Institute of Environmental Health Sciences [PI Gilliland]. Dr. Contreras was supported by a grant from the NIH T32ES013678. MEDALL and CHICOS Projects: The research leading to these results has received funding from the European Community’s Seventh Framework Program(Health–F2-grantagreements No. 261357 and 241604). Per cohort ABCD: Data of the Amsterdam Born Children and their Development cohort study used in this research was in part supported by funds from the Netherlands Organisation for Health Research and Development (ZonMw 40–00812-98–11010). The study sponsors had no role in study design, data analysis, interpretation of data, or writing of this report. BAMSE: We acknowledge all funding sources: The Swedish Research Council, The Swedish Heart and Lung Foundation, The Swedish Research Council for Working Life and Social Welfare, the Swedish Asthma and Allergy Association Research Foundation, The Swedish Research Council Formas, Stockholm County Council, and the European Commission’s Seventh Framework 29 Program Me DALL under grant agreement No.261357. We thank all the children and their parents for participating in the BAMSE cohort and the nurses and other staff members working in the BAMSE project. EDEN: We acknowledge all the funding sources for the EDEN study: Foundation for medical research (FRM), National Agency for Research (ANR), National Institute for Research in Public health (IRESP: TGIR cohorte santé 2008 program), French Ministry of Health (DGS), French Ministry of Research, INSERM Bone and Joint Diseases National Research (PRO-A) and Human Nutrition National Research Programs, Paris–Sud University, Nestlé, French National Institute for Population Health Surveillance (InVS),French National Institute for Health Education (INPES), the European Union FP7programmes (FP7/2007-2013, HELIX, ESCAPE, ENRIECO, Medall projects), Diabetes National Research Program (through a collaboration with the French Association of Diabetic Patients (AFD)), French Agency for Environmental Health Safety (now ANSES), Mutuelle Générale de l’Education Nationale a complementary health insurance (MGEN),French national agency for food security, French speaking association for the study ofdiabetes and metabolism (ALFEDIAM).We acknowledge the commitment of the EDEN mother-child cohort study group: I.Annesi-Maesano, JY. Bernard, J. Botton, M.A. Charles, P. Dargent-Molina, B. de Lauzon-Guillain, P. Ducimetière, M. de Agostini, B. Foliguet, , A. Forhan, X. Fritel, A. Germa, V.Goua, R. Hankard, B. Heude, M. Kaminski, B. Larroque†, N. Lelong, J. Lepeule, G.Magnin, L. Marchand, C. Nabet, F. Pierre, R. Slama, M.J. Saurel-Cubizolles, M.Schweitzer, O. Thiebaugeorges.The Generation R Study:The Generation R study is made possible by financial support from the Erasmus Medical Center, Rotterdam, the Erasmus University Rotterdam, the Netherlands Organization for Health Research and Development (ZonMw), the Netherlands Organisation for Scientific Research (NWO), the Ministry of Health, Welfareand Sport and the Ministry of Youth and Families. The project received funding from the European Union's Horizon 2020 research and innovation programme (LIFECYCLE project, grant agreement no 733206; 2016), the European Research Council (ERC-2014-CoG-648916) and from cofunded ERA-Net on Biomarkers for Nutrition and Health (ERAHDHL), Horizon 2020 (grant agreement no 696295; 2017), ZonMW The Netherlands (no529051014; 2017), Science Foundation Ireland (no SFI/16/ERA-HDHL/3360), and the European Union (ALPHABET project).The researchers are independent from the funders. The study sponsors had no role in study design, data analysis, interpretation of data, or writing of this report. INMA: Data used for this research was provided by the INMA-Environment and Childhood Project (www.proyectoinma.org). This study was funded by grants from Instituto de Salud Carlos III (Red INMA G03/176 and CB06/02/0041), Spanish Ministry of Health (FIS-PIO41436, PI06/0867, PI081151, and FIS-FEDER 03/1615, 04/1112,04/1931, 05/1079, 05/1052, 06/1213, 07/0314 and 09/02647), Generalitat de Catalunya-CIRIT 1999SGR00241, the Conselleria de Sanitat Generalitat Valenciana, Department of Health of the Basque Government (2005111093 and 2009111069), the ProvincialGovernment of Gipuzkoa (DFG06/004 and DFG08/001).KOALA: The collection of the data from the KOALA Birth Cohort Study used in this analysis was financially supported by Friesland Foods (now Friesland Campina),Netherlands Asthma Foundation (grant numbers 3.2.07.022 and 3.2.03.48), Netherlands Heart Foundation (grant number 2014 T037, the Netherlands Organization for Health Research and Development (Zon Mw Prevention Program number 1.210-00-090), Triodos Foundation, Phoenix Foundation, Raphaël Foundation, Iona Foundation, Foundation forthe Advancement of Heilpedagogie, all in the Netherlands. MAS:The MAS birth cohort was funded by grants from the German Federal Ministry ofEducation and Research (BMBF; reference numbers 07015633, 07 ALE 27, 01EE9405/5,01EE9406) and the German Research Foundation (DFG; reference number KE 1462/2-1).PIAMA: The PIAMA study has been funded by The Netherlands Organisation for Health Research and Development; The Netherlands Organisation for Scientific Research; The Netherlands Asthma fund; The Netherlands Ministry of Spatial Planning Housing, and the Environment; and The Netherlands Ministry of Health, Welfare and Sport. RHEA: The Rhea project was financially supported by European projects (EU FP6-003-Food-3-NewGeneris -Contract No16320, EU FP6 STREP Hiwate -Contract No36224,EU FP7 ENV.2007.1.2.2.2. Project No 211250 Escape, EU FP7-2008-ENV-1.2.1.4 Envirogenomarkers Contract No226756, EU FP7-HEALTH-2009-single stage CHICOS Contract No241604, EU FP7 ENV.2008.1.2.1.6. Proposal No 226285 ENRIECO, EU-FP7,Proposal No 264357 MeDALL, EU- FP7-HEALTH-2012 Proposal No 308333 HELIX),and the Greek Ministry of Health (Program of Prevention of obesity and neurodevelopmental disorders in preschool children, in Heraklion district, Crete, Greece:2011-2014; “Rhea Plus”: Prevention Program of Environmental Risk Factors for Reproductive Health, and Child Health: 2012-2015).ROBBIC: Data of the Rome cohort was in part supported byfunds from the Italian Ministry of Health (Programma speciale ex art. 12, comma 2, lettera b) del D. Lgs. 502/92,2001, 2003). We thank all the fields workers and the families for their contribution to thestudy. SWS: We thank the members of the Southampton Women's Survey Study group and the many participants in the SWS for their contribution to the study. The Southampton Women’s Survey is supported by grants from the Medical Research Council, British Heart Foundation, Food Standards Agency, British Lung Foundation, Arthritis Research UK, NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, and the European Union's Seventh Framework Programme (FP7/2007-2013), project Early Nutrition under grant agreement n°289346.