Bidirectional associations between adiposity and mental health: a prospective cohort study of the UK Biobank

Abstract Objective This study aimed to examine the bidirectional associations between indicators of adiposity and mental health. Methods Using longitudinal data from 60,319 UK Biobank participants, we explored the bidirectional associations between mental health (including neuroticism, recent depressive symptoms, probable depression status, stress, mania, life satisfaction, and happiness) and adiposity indicators (including BMI, waist circumference, body fat percentage, and different obesity types). Results The multivariate logistic regressions and mixed‐effects models revealed the following: 1) BMI and general obesity were bidirectionally associated with recent depressive symptoms, having probable depression status, experiencing at least one type of stress (especially stress from serious illness, injury, or assault to oneself or financial difficulties), and life satisfaction (especially health satisfaction and financial situation satisfaction); 2) waist circumference and abdominal obesity were bidirectionally associated with recent depressive symptoms and financial situation satisfaction; and 3) body fat percentage and high body fat percentage were bidirectionally associated with recent depressive symptoms, experiencing stress from financial difficulties, health satisfaction, and financial situation satisfaction. Conclusions The bidirectional associations between specific indicators of adiposity and mental health depend on the types of adiposity.