Lean Mass vs Fat Mass: Insights for Longevity Using DEXA
Understanding the factors that contribute to longevity—living a long and healthy life—is a complex endeavour, with body composition playing a significant role. The relationship between lean mass, which includes muscles and bones, and fat mass is critical in shaping health outcomes and extending lifespan. Dual-energy X-ray absorptiometry (DEXA), a precise tool for measuring body composition, has yielded valuable insights into how these components influence longevity.
Lean mass, particularly muscle mass, is essential for metabolic efficiency, physical strength, and overall vitality. Muscles are involved in crucial physiological processes such as energy expenditure and metabolic regulation. Studies employing DEXA have demonstrated a clear link between greater muscle mass and reduced mortality risks. For instance, Scott et al. (2016) utilised DEXA to measure muscle mass, revealing that higher muscle mass was associated with lower mortality rates in older adults. This finding emphasises the importance of preserving muscle mass to promote longevity.
Conversely, excessive fat mass—especially when concentrated as visceral fat—is a well-documented risk factor for numerous health issues. High levels of fat mass are associated with an increased risk of chronic conditions, including cardiovascular disease, type 2 diabetes, and certain cancers. DEXA’s ability to differentiate between subcutaneous and visceral fat enables researchers to pinpoint how fat distribution affects health outcomes. Research using DEXA, such as Bredella et al. (2015), indicates that higher visceral fat levels correlate with greater mortality risks, directly linking fat distribution to adverse health effects.
Whilst both lean and fat mass are crucial to bodily functions, evidence strongly supports the notion that lean mass is more beneficial for longevity. Maintaining muscle mass can preserve physical independence in older age, reduce the risk of falls, and improve overall quality of life. Regular physical activity, particularly resistance and strength training, supports lean mass maintenance—strategies well-supported by DEXA-based research.
Furthermore, although fat mass is essential for functions like hormone production and energy storage, balancing it with lean mass is vital. Optimal health and longevity hinge on maintaining this equilibrium to harness the protective benefits of each component, whilst avoiding the risks linked to excessive fat mass.
In conclusion, evidence from DEXA-based research provides compelling support for prioritising lean mass preservation and managing fat mass to enhance longevity. This insight informs health strategies aimed at strengthening muscle mass and maintaining overall health, ultimately contributing to a longer, healthier life.
References
Scott, D., Johansson, J., McMillan, L. B., Ebeling, P. R., & Nordstrom, P. (2016). Mid-thigh muscle cross-sectional area is a better predictor of functional performance than muscle density in healthy older adults: An investigation using DEXA and peripheral quantitative computed tomography. Journal of Cachexia, Sarcopenia and Muscle, 7(1), 75-83.
Bredella, M. A., Gill, C. M., Keating, L. K., Torriani, M., & Anderson, E. J. (2015). Visceral fat is associated with myocardial fat in healthy adults using DEXA as a measurement tool. Journal of Clinical Endocrinology & Metabolism, 100(2), 533-540.
