Negative life events predict weight gain in a 13-year follow-up of an adult Swedish population

Background: Increasing psychosocial stress may underlie contemporary obesity trends. We investigate cross-sectional and prospective associations between negative life events (NLEs) and anthropometric indicators, and whether these are explained by lifestyle, depression and sleeping problems. Methods: Participants in the Swedish INTERGENE cohort answered questions about ten types of NLE, and indicated whether they occurred during the last year or earlier (2001-04, n = 2706). Body mass index (BMI) and waist-to-hip ratio (WHR) were measured at baseline, and at follow-up (2014-16, n = 974). Numbers of recent and distant NLE were related to anthropometric variables using linear models including age, sex, and education, and further adjusted for lifestyle, and psychological problems. Prospective models were adjusted for baseline anthropometric values. Results: Participants reported on average 3.6 types of NLEs, of which 70% were experienced more than one year ago. At baseline, distant but not recent NLEs were associated with higher values of both BMI and WHR. These associations were explained in part by lifestyle and depression assessed at baseline. Recent but not distant NLEs predicted gain in BMI, 0.19 (0.07, 0.30) kg/m(2), and WHR, 0.005 (0.002, 0.007), per event and independent of baseline covariates. The largest associations were seen for job insecurity and financial worries, with 0.35 (0.17, 0.52) kg/m(2) increase in BMI corresponding to approximately 1.2 kg per event, in both sexes. Conclusion: We observed positive associations between NLEs and weight gain over 13 years including signs of latency and recovery regarding adverse weight development.