Understanding Bone Density Loss in Eating Disorders: Contributions of Weight Suppression and Speed of Weight Loss

<b>Background/Objectives:</b> Eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED), are associated with bone density loss. Weight suppression (WS) and weight loss speed (WLS) are two critical weight-related factors that may influence bone health, yet their relationship with bone density remains underexplored. This study aimed to investigate the associations between WS, WLS, and bone density in individuals with EDs, focusing on total body and spinal bone density. <b>Methods:</b> We examined 270 individuals with EDs (AN: n = 187, BN: n = 57, BED: n = 26) at the onset of inpatient treatment. WS and WLS were calculated from weight history, and bone density was assessed using dual-energy X-ray absorptiometry (DXA). Regression analyses were performed separately for each diagnosis. <b>Results:</b> In AN, both WS and WLS were significant predictors of total (<i>p</i> = 0.001) and spinal (<i>p</i> = 0.007) bone density. WS and WLS independently predicted total bone density, with WS significantly predicting spinal bone density. In BN and BED, only WLS showed significant associations with bone density. Minimum weight was a key predictor of bone density in AN, underscoring the importance of avoiding extremely low body weight. <b>Conclusions:</b> WS and WLS significantly affect bone density in AN, with WLS also predicting bone density in BN and BED. These findings highlight the need to monitor weight-related factors across ED populations. In AN, avoiding extremely low body weight is crucial for preserving bone health, while in BN and BED, managing WLS is key to mitigating bone density loss.