Exploring the changing association between parental and adolescent fruit and vegetable intakes, from age 10 to 30 years.

Background Adolescence is a pivotal developmental stage, where escalating rates of overweight and obesity have raised concerns about diet quality and its association with adverse health outcomes. Parents are known to have considerable influence on childhood diet, but how this influence changes as adolescents mature is unknown. This study investigates the association between parental fruit and vegetable (FV) intake and adolescent FV consumption, exploring how this changes across adolescence and when children leave home. Methods Adolescents aged 10-30 years (n=12,805) from the UK Household Longitudinal Study (UKHLS), and their parents, reported FV intakes every 2 years. Multilevel linear regression models were fitted to assess associations between parental and adolescent FV intakes, investigating interactions with age and living arrangement, and adjusting for sociodemographic covariates. Results Parental FV intake was positively associated with adolescent FV intake (β=0.20 [95%CI:0.19,0.22] portions/day), with the strength of this association lowest during early adolescence (10-14 years) and peaking at 17-18 years (β=0.30 [95%CI: 0.27,0.33] portions/day). When adolescents no longer lived in the parental home, the association of parental FV intake with their own FV consumption decreased, but a positive association was maintained up to age 30 years. Conclusions Our findings emphasise the enduring effect of parental modelling on dietary choices, highlighting the potential for interventions to promote increased FV intake, acknowledging the lasting influence of parental diet, even beyond the confines of the parental home. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was conducted as part of TBs PhD funded by Medical Research Council (MRC) Doctoral Training Partnership (DTP) and Elizabeth McDowell Studentship at Newnham College Cambridge [grant number SJAH/055 RG8693] and supported by the MRC Epidemiology Unit, University of Cambridge [grant numbers MC\_UU\_00006/5 and MC\_UU\_00006/7]. EMW is funded by a Career Development Award from the UK Medical Research Council [grant number MR/T010576/1]. JA was supported by the Medical Research Council [grant number MC\_UU\_00006/7]. ### 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: The University of Essex Ethics Committee has approved all data collection on Understanding Society main study, COVID-19 surveys and innovation panel waves, including asking consent for all data linkages except to health records. 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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The data that support the findings of this study are available on request from the UK Data Service, study number (SN) 6614. The data are publicly available, however, they are considered safeguarded and therefore require users to register and accept the End User Licence.