Background <p>Obesity, especially visceral obesity, is a major health issue globally, leading to metabolic disorders. Visceral fat accumulation is closely linked to insulin resistance and metabolic abnormalities. The role of branched-chain amino acids (BCAAs, e.g. leucine, isoleucine, and valine) in metabolic health, particularly in visceral obesity, remains unclear. Further investigation is needed to elucidate the relationships among body fat composition, BCAAs, and metabolic dysfunction in visceral obesity.</p> Purpose <p>This study investigates the correlation between serum BCAAs levels and body fat composition in individuals with visceral obesity, as well as the association between these levels and metabolic indicators. Methods: A total of 105 participants were recruited and categorized into three groups: obesity without type 2 diabetes mellitus (T2DM) (<i>n</i> = 52), obesity with T2DM (<i>n</i> = 32), and healthy controls (<i>n</i> = 21). All participants underwent assessments of anthropometric measurements, biochemical parameters, and serum amino acid profiles. Correlation tests and multiple linear regression models were used to analyze relationships among variables and potential associations.</p> Results <p>Serum BCAAs levels were significantly higher in both obese groups than in the healthy, normal-weight control group (<i>p</i> &lt; 0.001). Compared with the healthy normal-weight controls, valine showed the greatest increase (obesity non-T2DM: 36.48 ± 8.33 µg/mL; obesity and T2DM: 43.46 ± 7.68 µg/mL; controls: 30.48 ± 4.19 µg/mL). In Pearson’s analysis, BCAAs were positively associated with visceral fat area (VFA), body mass index (BMI), waist circumference (WC), body fat ratio, and IR-related markers (HOMA-IR, fasting insulin, and HbA1c) (all <i>p</i> &lt; 0.05). Valine demonstrated the strongest correlations with HOMA-IR (<i>r</i> = 0.481, <i>p</i> &lt; 0.001) and WC (<i>r</i> = 0.507, <i>p</i> &lt; 0.001). Strong positive correlations were also observed between BCAAs and fasting glucose, fasting insulin, HbA1c, and lipid parameters. In multivariable models, valine was independently and positively associated with central adiposity, as reflected by WC (standardized β = 0.357, <i>p</i> = 0.001), and with insulin resistance, as assessed by HOMA-IR (standardized β = 0.306, <i>p</i> = 0.003). Leucine and isoleucine were independently associated with WC and fasting insulin levels, while no independent associations were observed for phenylalanine or tyrosine.</p> Conclusion <p>Valine is associated with central adiposity and insulin resistance in obesity and was independently associated with WC and HOMA-IR. BCAAs profiling may help identify individuals with increased metabolic risk; however, further prospective studies are required to validate its clinical and predictive value.</p> Trial Registration <p>Not applicable</p>