Risk of severe obesity development: Examining the role of psychological well-being related measures and sociodemographic factors in two longitudinal UK cohort studies

Objective: To examine the prospective association between psychological well-being related measures and severe obesity development in young and middle-aged UK adults. Design: A longitudinal analysis of two cohort studies. Methods: We used data from the National Child and Development Study (NCDS) and the British Cohort Study (BCS) to examine the association between baseline psychological well-being related measures (depressive symptoms, life satisfaction, and self-efficacy) and severe obesity development (defined as body mass index – BMI ≥35) and residualised BMI change scores at follow-up. We analysed repeated measures of baseline and follow-up pairs with 6- to 7-year follow-up on average (n = 22,390 and 23,811 observations in NCDS and BCS, respectively) using panel data analysis and controlling for sociodemographic factors. We conducted additional analyses using analytical sample sizes with longer follow-up (16-17 years). Results: Although a range of sociodemographic factors (e.g., being female, non-married) were associated with increased risk of severe obesity development, we found limited evidence that psychological well-being related measures were associated with severe obesity development across cohorts and pooled analyses. Depressive symptoms, life satisfaction, and self-efficacy were however associated with relatively small changes in continuous BMI change across analyses and this tended to be limited to participants without obesity (BMI 18.5 – <30) and not those already living with obesity (BMI 30 – <35) at baseline. Conclusions: Although poorer psychological well-being is associated with modest changes in body weight in individuals without obesity, there is limited evidence that psychological well-being related measures prospectively predict the development of severe obesity.