Genetic and Environmental Effects on BMI Fluctuation Across the Adult Life Course and Its Associations With Baseline BMI and BMI Change: An Individual‐Based Study of 14 Longitudinal Twin CohortsInstitute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Finland ; Clinicum, Department of Psychiatry, University of Helsinki, Finland.
Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Finland ; Minerva Foundation Institute for Medical Research, Helsinki, Finland.
Department of Twin Research and Genetic Epidemiology, King's College, London, UK.
Department of Twin Research and Genetic Epidemiology, King's College, London, UK.
The Danish Twin Registry, Institute of Public Health, Epidemiology, Biostatistics & Biodemography, University of Southern Denmark, Odense, Denmark.
The Danish Twin Registry, Institute of Public Health, Epidemiology, Biostatistics & Biodemography University of Southern Denmark, Odense, Denmark.
Research Unit of Clinical Genetics, Department of Clinical Research University of Southern Denmark, Odense, Denmark ; Odense University Hospital, Odense, Denmark.
Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
Institute for Behavioral Genetics, University of Colorado, Boulder, Colorado, USA.
Department of Psychology and Neuroscience, University of Colorado, Boulder, Colorado, USA.
Centre for Behavioural Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy.
Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden.
Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden.
QIMR Berghofer Medical Research Institute, Brisbane, Australia.
QIMR Berghofer Medical Research Institute, Brisbane, Australia.
Washington State Twin Registry, Washington State University—Health Sciences Spokane, Washington, USA.
Washington State Twin Registry, University of Washington, Seattle, Washington, USA.
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
Department of Biological Psychology, Vrije Universiteit Amsterdam, the Netherlands ; Amsterdam Public Health Research Institute, the Netherlands.
Department of Biological Psychology, Vrije Universiteit Amsterdam, the Netherlands ; Amsterdam Public Health Research Institute, the Netherlands.
Department of Biological Psychology, Vrije Universiteit Amsterdam, the Netherlands ; Amsterdam Public Health Research Institute, the Netherlands.
Center for Economic and Social Research, University of Southern California, Los Angeles, California, USA.
Health and Medicine Division, the National Academies of Sciences, Engineering, and Medicine, Washington DC, USA.
Department of Epidemiology, Seoul National University School of Public Health, Korea.
Institute of Health & Environment, Seoul National University, Korea.
Institute of Health & Environment, Seoul National University, Korea.
Department of Biological Psychology, Vrije Universiteit Amsterdam, the Netherlands ; Amsterdam Public Health Research Institute, the Netherlands.
Department of Biological Psychology, Vrije Universiteit Amsterdam, the Netherlands ; Amsterdam Public Health Research Institute, the Netherlands.
QIMR Berghofer Medical Research Institute, Brisbane, Australia.
Amsterdam Public Health Research Institute, the Netherlands ; Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, the Netherlands.
Institute for Molecular Medicine Finland, HiLIFE, University of Helsinki, Finland.
Helsinki Institute for Demography and Population Health, University of Helsinki, Finland.
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2026 (English)In: Diabetes, obesity and metabolism, ISSN 1462-8902, E-ISSN 1463-1326, article id dom.71040Article in journal (Refereed) Published
Abstract [en]
Introduction: Body mass index (BMI) fluctuation has adverse health consequences, yet its determinants remain poorly understood. We examined genetic and environmental influences on BMI fluctuation and its associations with BMI trajectories.
Data and Methods: Data from 14 longitudinal twin cohorts, including 58 311 individuals (54% women) and 22 714 complete twin pairs (9761 monozygotic), were pooled. BMI trajectories from ages 18 to 99 years were estimated using linear mixed-effects models. BMI fluctuation was defined as the average squared residual between observed and expected BMI around individual trajectories. Genetic and environmental contributions to BMI fluctuation and its associations with baseline BMI and BMI change were assessed using structural equation modelling.
Results: Additive genetic effects explained a moderate proportion of variance in BMI fluctuation (a2 = 0.20 in men, 0.29 in women), with the remainder attributable to unique environmental effects (e2 = 0.80 and 0.71). No evidence of sex-specific genetic effects was found. Genetic contributions varied across life stages, peaking in men at ages 31–50 (a2 = 0.36) and in women at 51–65 (a2 = 0.36). Higher baseline BMI was associated with greater fluctuation, whereas greater directional BMI change was associated with less fluctuation. Higher BMI at ages 18–30 was associated with greater subsequent BMI fluctuation across later adulthood stages. Previous associations were driven by both genetic and unique environmental factors.
Conclusions: BMI fluctuation was predominantly explained by unique environmental effects, with moderate heritability that varied across life stages with no evidence of sex-specific genetic effects. Genetic and environmental factors contribute to how BMI fluctuation is associated with BMI change.
Place, publisher, year, edition, pages
John Wiley & Sons, 2026. article id dom.71040
Keywords [en]
body composition, cohort study, meta-analysis, observational study
National Category
Public Health, Global Health and Social Medicine
Research subject
Wellbeing in long-term health problems (WeLHP)
Identifiers
URN: urn:nbn:se:his:diva-26908DOI: 10.1111/dom.71040ISI: 001804299500001PubMedID: 42351399Scopus ID: 2-s2.0-105042995849OAI: oai:DiVA.org:his-26908DiVA, id: diva2:2085535
Funder
Wellcome trustForte, Swedish Research Council for Health, Working Life and Welfare, 2017‐00641NIH (National Institutes of Health), RC2 HL103416NIH (National Institutes of Health), P01 AG08761Forte, Swedish Research Council for Health, Working Life and Welfare, 2017-00641
Note
CC BY 4.0
Correspondence: Alvaro Obeso Fernandez, alvaro.obeso@helsinki.fi
First published: 25 June 2026
This work was supported by the Chronic Disease Research Foundation, the Medical Research Council Laboratory of Molecular Biology, the Swiss State Secretariat for Education, Research and Innovation (SERI), the MagW/ZonMW, (912-10-020, 400-05-717, 451-04-034, 463-06-001, 480-04-004, 904-61-090, 904-61-193, 985-10-002, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192), the Clinical Center, R21 AG039572, the Wellcome Trust, the National Institute for Health and Care Research, the VU University's Institute for Health and Care Research, EMGO+, the European Research Council (ERC 230374), the Versus Arthritis, the NIHR Clinical Research Network North West London, the Terveyden Tutkimuksen Toimikunta (100499, 118555, 141054, 205585, 264146, 308248), the Avera Institute for Human Genetics, the Danish Agency for Science and Higher Education, the Centre for Behavioural Sciences and Mental Health, the Velux Fonden, the Horizon Europe Research and Innovation programme (101080117), the Zoe Ltd, the Research Council for Health and Disease, the Research council of Finland Centre of Excellence in Complex Disease Genetics (352792), the European Union Horizon 2020, the Centre of Research Excellence Grant (1079102), the National Institute of Health (RC2 HL103416), the Wellcome Leap Dynamic Resilience Programme, the National Institute of Health US (P01 AG08761), the NIHR Barts Biomedical Research Centre, Queen Mary University of London, the Forskningsrådet om Hälsa, Arbetsliv och Välfärd (2017-00641), the National Institute of Alcohol Abuse and Alcoholism (AA-00145, AA-09203, AA-12502, AA015416, AA15416), the UK Research and Innovation (UKRI) (10093560, 10106435) and the Global Research Network Program of the National Research Foundation (NRF 2011-220-E00006).
2026-07-092026-07-092026-07-09Bibliographically approved