A longitudinal causal graph analysis investigating modifiable risk factors and obesity in a European cohort of children and adolescents

A Cohort Causal Graph (CCG) over the life-course from childhood to adolescence is estimated to identify potential causes of obesity and to determine promising targets for prevention strategies. We adapt a popular causal discovery algorithm to deal with missing values by multiple imputation and with temporal cohort structure. To estimate possible causal effects of modifiable risk factors at baseline on obesity six years later, we used the “Intervention-calculus when the Directed Acyclic Graph is Absent” and double machine learning with confounder adjustment based on the obtained CCG. Causal relations among 51 variables were analysed including obesity, early life factors, lifestyle and cultural background of 5,112 children from the European IDEFICS/I.Family cohort across three waves (2007-2014). The resulting CCG shows some but not many and only indirect possible pathways from earlier modifiable risk factors such as audio-visual media consumption (AVM) to later obesity. The estimated causal effects suggested that promising interventions would encourage longer sleep or reduce AVM during childhood, both slightly decreasing expected body mass index six years later. But overall, no or only weak causal effects could be found for hypothetical interventions on individual behaviors in early childhood on later obesity. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement German Research Foundation (DFG, DI 2372/1-1). European Commission, Sixth RTD Framework Programme Contract No. 016181 (FOOD) European Commission, Seventh RTD Framework Programme Contract No. 266044 (KBBE 2010-14) Joint Programming Initiative "A Healthy Diet for a Healthy Life" (JPI HDHL) ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: 1. Ethics Committee of the Gent University Hospital (Belgium) gave ethical approval for this work (15/10/2007, ref: No. EC UZG 2007/243 and 19/02/2013, No. B670201316342) 2. Cyprus National Bioethics Committee (Cyprus) gave ethical approval for this work (12/07/2007, ref: No. EEBK/EM/2007/16 and 21/Feb/2013, No. EEBK/ETI/2012/33 3. Tallinn Medical Research Ethics Committee (TMREC, Estonia) gave ethical approval for this work (14/06/2007, ref: No. 1093 and 17/January 2013, No. 128) 4. Ethic Commission of the University of Bremen (Germany) gave ethical approval for this work (16/01/2007 and 11/12/2012) 5. Medical Research Council (Hungary) gave ethical approval for this work (21/Jun/2007, ref: 22-156/2007-1018EKU and 18/12/2012, 4536/2013/EKU) 6. Ethics Committee of the Local Health Authority (ASL) in Avellino (Italy) gave ethical approval for this work (19/06/2007, ref: No. 2/CE and 18/Sep/2012, No. 12/12) 7. Ethics Committee for Clinical Research of Aragon (CEICA, Spain) gave ethical approval for this work (20/06/2007, ref:No. PI07/13 and 13/Feb/2013, No. PI13/0012) 8. Regional Ethics Research Board in Gothenburg (Sweden) gave ethical approval for this work (30/07/2007, ref: No. 264-07 and 10/Jan/2013, No. 927-12) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors.