Diet quality and psychological resilience in women with breast cancer undergoing chemotherapy

Psychological resilience may be related to dietary behaviors, self-care capacity, and overall diet quality during cancer treatment. This study examined the association between recalled-day Healthy Eating Index-2015 (HEI-2015) and psychological resilience, together with selected participant characteristics and food-consumption frequencies, among women with breast cancer undergoing chemotherapy. This cross-sectional study included 104 women receiving chemotherapy at two hospitals in Erzurum, Türkiye, between July and September 2023. Data were collected using a personal information form, a single 24-hour dietary recall, a food consumption frequency form, and the Brief Resilience Scale (BRS). The HEI-2015 score was calculated from a single 24-hour dietary recall. The primary association between recalled-day HEI-2015 and psychological resilience was examined using simple and hierarchical multiple linear regression. Secondary and exploratory analyses were adjusted for multiple comparisons using the Benjamini–Hochberg false discovery rate (FDR) procedure. The median BRS score was 19.50 (Q1–Q3: 16.00–23.00), and the median recalled-day HEI-2015 score was 43.76 (Q1–Q3: 34.67–53.25). In unadjusted regression, higher recalled-day HEI-2015 were associated with higher psychological resilience (B = 0.073, β = 0.238, p = .015; R² = 0.057). After adjustment for education level, perceived social support, exercise status, and nausea, recalled-day HEI-2015 remained positively associated with psychological resilience (B = 0.064, β = 0.209, p = .042). The final model explained 10.8% of variance (R² = 0.108 and adjusted R² = 0.062). In secondary analyses, exercise was associated with higher BRS and recalled-day HEI-2015, but neither remained significant after FDR correction. In exploratory analyses, fresh fruit (ρ = 0.453) and fresh vegetable consumption frequencies (ρ = 0.379) were positively associated with recalled-day HEI-2015 after FDR correction. Higher recalled-day HEI-2015 was positively associated with greater psychological resilience among women receiving chemotherapy for breast cancer, after adjustment for the covariates included in the regression model. Given the limited explained variance, cross-sectional design, and single-day dietary assessment, the findings should be interpreted cautiously. Longitudinal studies using repeated dietary assessments are needed to examine whether this association persists over time and to clarify its temporal and clinical relevance.