Psychological distress and quality of life in Iranian adolescents with overweight/obesity: mediating roles of weight bias internalization and insomnia

Purpose: To examine whether weight-related self-stigma (aka weight bias internalization) and insomnia are potential predictors of psychological distress and quality of life (QoL) among Iranian adolescents with overweight (OW)/obesity (OB). To examine whether weight-related self-stigma and insomnia are potential mediators in the relationship between excess weight and health outcomes of distress and QoL. Methods: All participants (n = 934; 444 males; mean age = 15.7 ± 1.2 years; zBMI = 2.8 ± 1.0) completed questionnaires on weight-related self-stigma and insomnia at baseline. Six months later, they completed questionnaires on psychological distress and QoL to assess health outcomes. Relationships among variables were tested using mediation analyses with bootstrapping method. Results: Weight-related self-stigma significantly mediated the effects of zBMI on psychological distress (effect = 0.22; bootstrapping SE = 0.09; 95% CI = 0.08, 0.45), psychosocial QoL (effect = − 0.64; bootstrapping SE = 0.19; 95% CI = − 1.10, − 0.32), and physical QoL (effect = − 1.35; bootstrapping SE = 0.54; 95% CI = − 2.43, − 0.26). Insomnia also significantly mediated the effects of zBMI on psychological distress (effect = 2.18; bootstrapping SE = 0.31; 95% CI = 1.61, 2.81), psychosocial QoL (effect = − 0.89; bootstrapping SE = 0.33; 95% CI = − 1.60, − 0.28), and physical QoL (effect = − 0.83; bootstrapping SE = 0.42; 95% CI = − 1.69, − 0.02). Full mediations were found in psychosocial QoL; partial mediations were found in psychological distress and physical QoL. Conclusions: Weight-related self-stigma and insomnia were significant mediators in the effects of excess weight on health outcomes. Therefore, it is important to identify and treat weight-related self-stigma and insomnia for adolescents with OW/OB. Level of evidence: Level V, cross-sectional descriptive study.