Abstract
Objective: This study aimed to examine the mediating and moderating roles of quality of life, mindfulness, and savoring in the relationship between sugar intake and depression among women with breast cancer undergoing active treatment. Methods: This prospective observational study recruited seventy-eight women diagnosed with breast cancer within six months from a medical center in Taiwan. The participants completed patient-reported health surveys and dietary recalls. Results: Sugar consumption (β = 0.22, p < 0.01) and breast symptoms (β = 0.28, p < 0.01) were significantly associated with depressive symptoms. Simple mediation analysis indicated that quality of life fully mediated the relationship between sugar intake and depression (indirect effect = 0.15, 95% CI = 0.05 to 0.25), while breast symptoms played a partial mediating role (indirect effect = 0.10, 95% CI = 0.02 to 0.18). Moderated mediation analysis revealed that after-event savoring moderated the path between quality of life and depression (interaction effect = -0.04, 95% CI = -0.08 to -0.01). Furthermore, non-judgment mindfulness significantly attenuated the indirect effect of sugar consumption on depression via quality of life functions (moderated mediation index = -0.03, 95% CI = -0.06 to -0.00). Conclusions: Mindfulness and momentary savoring may act as protective factors, moderating the relationship between sugar consumption and depression. These findings support the proposal to integrate nutrition and mindfulness-based support into clinical care for women receiving active breast cancer treatment.