Health beliefs and quality of life in patients with gastric cancer: the chain mediating role of nutritional behaviors and nutritional status

Background Patients with gastric cancer often have reduced quality of life (QoL). This study aimed to examine whether nutritional behaviors and nutritional status serially mediate the association between health beliefs and QoL among patients with gastric cancer. Methods This cross-sectional study included 274 patients with gastric cancer. Health beliefs, QoL, nutritional behaviors, and nutritional status were measured using validated instruments. Pearson correlation analysis was performed to examine bivariate relationships. Serial mediation analysis was conducted using structural equation modeling with bootstrap resampling (5,000 samples). Results Health beliefs were positively correlated with QoL ( r = 0.323, P < 0.01). The total effect of health beliefs on QoL was significant (effect = 0.595, P < 0.05). After including mediators, the direct effect remained significant (effect = 0.284, P < 0.05), accounting for 47.7% of the total effect. The indirect effect via nutritional behaviors alone was significant (effect = 0.150, P < 0.05), explaining 25.2% of the total effect. The indirect effect via nutritional status alone was also significant (effect = 0.103, P < 0.05), explaining 17.3% of the total effect. The serial indirect effect (health beliefs → nutritional behaviors → nutritional status → QoL) was significant (effect = 0.058, P < 0.05), accounting for 9.7% of the total effect. The model demonstrated excellent fit ( χ ²/ df = 1.260, CFI = 0.992, RMSEA = 0.031, TLI = 0.989, GFI = 0.965, AGFI = 0.947). Conclusion Health beliefs are positively associated with QoL in patients with gastric cancer, with evidence of independent and serial mediation by nutritional behaviors and nutritional status. These findings are compatible with the hypothesized theoretical model and support the development of theory-driven interventions for future testing in prospective studies.