Poster Presentation ESA-SRB-ANZOS 2025 in conjunction with ENSA

The Role of Fat-Free Mass in Weight-Related Complications in Adults: A Rapid systematic Review (129103)

Tadesse Asmamaw Dejenie 1 , Paul Fahey 1 , Haider Mannan 1 , Mohammad Ariya 1 , Evan Atlantis 1 2
  1. Health Sciences , Western Sydney University, Campbelltown, NSW, Australia
  2. Translational Health Research Institute, Western Sydney University, Campbelltown, NSW, Australia

Aim: To synthesise evidence from observational studies assessing the role of fat-free mass in weight-related complications in adults with overweight or obesity.

Methods: We systematically searched Medline, Embase, Web of Science, and Google Scholar, including observational studies on adults (≥18 years) with overweight or obesity. Effect estimates (risk ratios, odds ratios, hazard ratios) were logarithmically transformed and harmonized to a common reference. Pooled random-effects meta-analyses were conducted for outcomes with three or more studies. Heterogeneity was quantified using the I2 statistic; when substantial (I2 > 50%), τ2) was also considered. Subgroup and sensitivity analyses explored heterogeneity.

Results: Meta-analysis of six studies revealed low FFM to be associated with an increased risk of developing type 2 diabetes mellitus (pooled RR=1.43; 95% CI: 1.15–1.79). Although high heterogeneity was observed (I2=90.3%; τ2=0.07), sex-stratified analyses showed similar effects for men and women. Four studies indicated low FFM significantly increased risk of having metabolic syndrome (pooled RR=3.40; 95% CI: 1.63–7.06). High heterogeneity was also observed (I2=91.6%; τ2 =0.49), with consistency across sexes. Three studies showed low FFM was associated with over a twofold increased risk of developing cardiovascular disease (pooled RR = 2.03; 95% CI: 1.27–3.26), with low to moderate heterogeneity (I2=36.1%; τ2 =0.08). Three studies demonstrated low FFM was associated with more than twice the risk of having non-alcoholic fatty liver disease (pooled RR = 2.24; 95% CI: 1.52–3.32), with substantial heterogeneity (I2=69.9%; τ2=0.08). Sensitivity analyses generally affirmed the robustness of these associations.

Conclusion: Low FFM significantly increases the risk of type 2 diabetes, metabolic syndrome, cardiovascular disease, and non-alcoholic fatty liver disease. These associations were largely consistent across sexes, highlighting the critical importance of maintaining adequate FFM to mitigate weight-related health risks in both men and women.