Are all risks equal? Understanding the differential mechanism linking early environmental risk and obesity via the interplay of mental health and lifestyle factors.
Are all risks equal? Understanding the differential mechanism linking early environmental risk and obesity via the interplay of mental health and lifestyle factors.
BACKGROUND: The mechanisms linking early environmental risk (EER) and obesity via the interplay of mental health and lifestyle factors in the early life stage remain unclear.
OBJECTIVE: To examine whether EER was associated with later mental health, lifestyle factors and obesity and to identify the mediating roles of mental health and lifestyle in these relationships.
METHOD: Using data from the Millennium Cohort Study (valid n=5401), we longitudinally assessed the relationship between EER (prenatal risks, neonatal risks, low socioeconomic status, maternal psychological problems and harsh parenting; 9 months to age 3 years), mental health problems in childhood (internalising and externalising problems; age 7 years), lifestyle factors in early adolescence (diet, exercise, smoking and drinking; age 11 years) and obesity in late adolescence (age 14-17 years). Structural equation modelling was used to test proposed pathways.
FINDINGS: The proposed model showed an acceptable fit (Comparative Fit Index=0.926, Tucker-Lewis Index=0.875, root mean square error of approximation=0.034, standardised root mean square residual=0.046). EER was significantly associated with later mental health problems, lifestyle factors (ie, diet, exercise, smoking) and obesity. Higher EER was modestly associated with higher obesity risk via the interplay of externalising problems and drinking (β=0.01, p=0.036). The sex-stratified model results indicated differences between males and females.
CONCLUSION: By highlighting the importance of EER and the mediating role of lifestyle factors in mental health and later obesity risk, our findings provide evidence of shared risk mechanisms linking mental and physical health.
CLINICAL IMPLICATIONS: These findings suggest that integrating mental health assessment (especially externalising symptoms) with routine screening for adolescent alcohol use and other risk factors could inform more targeted obesity prevention in clinical and public health settings.
Sun, Hongyi
f8ca1e0e-b073-49c2-a489-4d0cbc27b4f1
Kiri, Janet
c72113ab-1cca-4a3d-a908-eca007516a72
Brandt, Valerie
e41f5832-70e4-407d-8a15-85b861761656
Golm, Dennis
ae337f61-561e-4d44-9cf3-3e5611c7b484
3 March 2026
Sun, Hongyi
f8ca1e0e-b073-49c2-a489-4d0cbc27b4f1
Kiri, Janet
c72113ab-1cca-4a3d-a908-eca007516a72
Brandt, Valerie
e41f5832-70e4-407d-8a15-85b861761656
Golm, Dennis
ae337f61-561e-4d44-9cf3-3e5611c7b484
Sun, Hongyi, Kiri, Janet, Brandt, Valerie and Golm, Dennis
(2026)
Are all risks equal? Understanding the differential mechanism linking early environmental risk and obesity via the interplay of mental health and lifestyle factors.
BMJ Mental Health.
(doi:10.1136/bmjment-2025-302211).
Abstract
BACKGROUND: The mechanisms linking early environmental risk (EER) and obesity via the interplay of mental health and lifestyle factors in the early life stage remain unclear.
OBJECTIVE: To examine whether EER was associated with later mental health, lifestyle factors and obesity and to identify the mediating roles of mental health and lifestyle in these relationships.
METHOD: Using data from the Millennium Cohort Study (valid n=5401), we longitudinally assessed the relationship between EER (prenatal risks, neonatal risks, low socioeconomic status, maternal psychological problems and harsh parenting; 9 months to age 3 years), mental health problems in childhood (internalising and externalising problems; age 7 years), lifestyle factors in early adolescence (diet, exercise, smoking and drinking; age 11 years) and obesity in late adolescence (age 14-17 years). Structural equation modelling was used to test proposed pathways.
FINDINGS: The proposed model showed an acceptable fit (Comparative Fit Index=0.926, Tucker-Lewis Index=0.875, root mean square error of approximation=0.034, standardised root mean square residual=0.046). EER was significantly associated with later mental health problems, lifestyle factors (ie, diet, exercise, smoking) and obesity. Higher EER was modestly associated with higher obesity risk via the interplay of externalising problems and drinking (β=0.01, p=0.036). The sex-stratified model results indicated differences between males and females.
CONCLUSION: By highlighting the importance of EER and the mediating role of lifestyle factors in mental health and later obesity risk, our findings provide evidence of shared risk mechanisms linking mental and physical health.
CLINICAL IMPLICATIONS: These findings suggest that integrating mental health assessment (especially externalising symptoms) with routine screening for adolescent alcohol use and other risk factors could inform more targeted obesity prevention in clinical and public health settings.
Text
Paper 2_SEM_20260209_Clean Version
- Accepted Manuscript
More information
Published date: 3 March 2026
Additional Information:
© Author(s) (or their employer(s)) 2026. Re-use permitted under CC BY-NC. Published by BMJ Group.
Identifiers
Local EPrints ID: 509989
URI: http://eprints.soton.ac.uk/id/eprint/509989
ISSN: 2755-9734
PURE UUID: 14a975aa-bee0-45bb-ae5b-25b6727bdab1
Catalogue record
Date deposited: 12 Mar 2026 17:50
Last modified: 13 Mar 2026 03:05
Export record
Altmetrics
Contributors
Author:
Hongyi Sun
Author:
Janet Kiri
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics