Gastric cancer (GC) remains a leading cause of cancer-related mortality worldwide, necessitating the identification of reliable prognostic indicators to enhance treatment outcomes. Recent research has highlighted the triglyceride-glucose (TyG) index as a potential surrogate marker for insulin resistance, which may significantly influence the prognosis of patients undergoing immunotherapy combined with chemotherapy. In this context, the study by Yao demonstrates that a high TyG index correlates with improved overall survival and progression-free survival in advanced GC patients receiving sintilimab and chemotherapy. Specifically, patients in the high TyG group had a significantly longer median progression-free survival of 9.8 months [95% confidence interval (CI): 9.2-10.9] compared to 8.0 months (95%CI: 7.5-8.5) in the low TyG group (hazard ratio = 0.58, 95%CI: 0.43-0.79, < 0.001). Similarly, the median overall survival was significantly longer in the high TyG group at 23.1 months (95%CI: 21.2-NA) 16.5 months (95%CI: 13.9-18.3) in the low TyG group (hazard ratio = 0.30, 95%CI: 0.21-0.42, < 0.001). These findings underscore the strong prognostic potential of the TyG index in guiding treatment strategies for advanced GC. These findings underscore the need for further investigation into the TyG index's role as a prognostic tool and its underlying mechanisms in influencing treatment efficacy. We advocate for additional multicenter studies to validate these results and explore the TyG index's applicability across diverse patient populations, ultimately aiming to refine treatment strategies and improve patient outcomes in advanced GC.