OBESITY, WEIGHT LOSS, AND BONE FRAGILITY: MUSCULOSKELETAL EFFECTS AND THERAPEUTIC INTERVENTIONS

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Introduction: The rise in obesity among adults and the elderly has increased c oncern about its musculoskeletal repercussions, especially due to the risk of bone fragility associated with aging, type 2 diabetes mellitus (T2DM), and sarcopenia. Although obese individuals often have higher bone mineral density (BMD), recent evidence indicates compromised trabecular microarchitecture and poorer bone quality, demonstrated by lower trabecular bone score (TBS) values and greater muscle fat infiltration. In addition, chronic systemic inflammation associated with obesity contributes to an increased risk of fractures even in individuals with preserved BMD. Objectives: This review investigated the relationship between obesity and bone fragility, evaluating the effects of weight loss, physical exercise, and pharmacological therapies on bone density, bone quality, and biomechanical strength. Methods: This narrative review was based on a literature search conducted in the PubMed database using the MeSH terms “Obesity,” “Bone Density,” “Bone Quality,” “Weight Loss,” and “Fracture Risk,” combined with Boolean operators. Randomized clinical trials and observational studies published between 2025 and 2026 were reviewed, emphasizing the relationship between obesity, weight loss, and skeletal health in overweight or obese adults. Studies involving animals, pediatric populations, duplicated articles, and papers not directly related to skeletal health in obesity were excluded Results and Discussion: The studies analyzed demonstrated that intentional weight loss of approximately 10% was associated with a 1% to 2% reduction in hip BMD, even when combined with resistance training strategies. However, intensive interventions combining a hypocaloric diet, aerobic exercise, and strength training were able to preserve bone quality parameters and biomechanical compete nce, despite reductions in BMD. In individuals with type 2 diabetes, an increased risk of clinical fractures associated with the use of insulin and thiazolidinediones was observed, suggesting that BMD alone does not adequately reflect bone strength in this population. Additionally, anti -obesity therapies involving GLP -1 receptor agonists, such as liraglutide, promoted reductions in body weight and BMI, although accompanied by absolute lean mass loss, potentially increasing the risk of osteosarcopenia. Conclusion: Although obesity is associated with higher BMD, it can coexist with poorer bone quality and increased skeletal fragility. Weight loss, especially when rapid or associated with a reduction in lean mass, may further intensify this process. Conversely, interventions that combine aerobic and resistance exercises appear to preserve skeletal biomechanical integrity. Therefore, the assessment of bone health in obese individuals should include parameters of bone quality and body composition, in addition to bone mineral density alone.