Peer-reviewed article
Body mass index and workplace bullying: exploring causality in two general population Norwegian surveys, the HUNT study and the Norwegian Mother, Father and Child Cohort Study (MoBa).
Hughes AM, Vie GÅ, Havdahl A, Mignon D, Hansen Edwards C ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This peer-reviewed study examines the relationship between body mass index and workplace bullying in two Norwegian adult population surveys. Using genetic analysis and longitudinal data, researchers found mixed evidence that higher BMI increases bullying risk, but clearer evidence that bullying itself leads to weight gain over time. The work focuses on working-age adults rather than children.
Key points
- Cross-sectional analysis showed participants with higher BMI were slightly more likely to report workplace bullying
- Genetic instrumental variable analysis found inconclusive evidence that BMI causally increases workplace bullying risk
- Longitudinal analysis found workplace bullying in 2006-2008 was associated with higher BMI in 2017-19
- Results suggest workplace bullying may affect body weight through psychosocial stress mechanisms
- The study involved 32,826 participants in HUNT and 14,076 mothers in MoBa
Limitations
This study focuses exclusively on working-age adults and does not address child well-being outcomes. The research examines associations between BMI and workplace bullying in general populations rather than evaluating an intervention to improve child health or protect children from harm.
Abstract
Introduction To interrogate whether reported associations between body mass index (BMI) and workplace bullying (WPB) reflect an impact of weight on bullying, an impact of bullying on weight or confounding. Methods We use data from working-age participants in two large, general population Norwegian surveys, the Trøndelag Health Study (HUNT, N=32 826) and the Norwegian Mother, Father and Child Cohort Study (MoBa mothers, N=14 076). To interrogate causal mechanisms, we apply genetic instrumental variable analysis (Mendelian randomisation) and, in HUNT only, bidirectional longitudinal analysis. Results In cross-sectional analysis in both surveys, participants with a higher BMI were slightly more likely to report concurrent WPB, adjusted for confounders including socioeconomic position and psychological distress (meta-analysed absolute risk difference, ARD: 0.22% per kg/m2, 95% CI 0.15 to 0.29, meta-analysed OR: 1.02 per kg/m2, 95% CI 1.01 to 1.03). Genetic analysis found strong evidence for an impact of BMI on WPB only in MoBa, but not overall (meta-analysed ARD: 0.32% per kg/m2, 95% CI -0.29 to 0.93). In longitudinal analyses using HUNT data, there was less evidence that earlier BMI affected WPB onset (ARD: 0.08% per kg/m2, 95% CI -0.10 to 0.25, with raised risk for participants with class I but not class II obesity at baseline). However, WPB in 2006-2008 was associated with higher BMI in 2017-19 (beta: 0.16 kg/m2 (95% CI 0.02 to 0.29)). Stratified analyses found inconsistent evidence of age, sex and socioeconomic modification, but suggested stronger associations pre-2020. Conclusions In two large Norwegian surveys, we found inconclusive evidence from genetic models that higher BMI increased the risk of WPB. Longitudinal analysis (possible only in HUNT) found mixed evidence that higher BMI increased risk of WPB, but clearly suggested that WPB affected BMI over time, consistent with an impact of psychosocial stress on BMI. Results underscore the negative consequences of WPB for physical as well as mental health.