Mediterranean Diet Adherence and Nutritional Status in Older Adults with Heart Failure with Reduced Ejection Fraction: A Cross-Sectional Study

Background/Objectives: Malnutrition is common in older adults with heart failure (HF). We examined the association between Mediterranean diet (MedDiet) adherence and nutritional status in older adults with HF with reduced ejection fraction (HFrEF), their relationship with resting left ventricular ejection fraction (LVEF), and nutrient intake relative to reference values. Methods: This cross-sectional study included 125 consecutive outpatients aged ≥ 65 years with HFrEF (LVEF ≤ 40%) in Türkiye, assessed in April–May 2020, during a COVID-19 stay-at-home restriction for this age group. Nutritional status was assessed with the Mini Nutritional Assessment (MNA), MedDiet adherence with the Mediterranean Diet Adherence Screener (MEDAS), and nutrient intake with a single 24 h recall compared with the Estimated Average Requirement (EAR). Results: The mean age was 72.9 ± 6.7 years. The MNA classified 15.2% of participants as malnourished and 49.6% as at risk of malnutrition; 30.4%, 43.2%, and 26.4% had low, moderate, and high MedDiet adherence. MNA and MEDAS categories showed a modest association (χ2(4) = 11.26, p = 0.024; Cramér’s V = 0.21). Each MEDAS point was associated with higher adjusted odds of a better MNA category (odds ratio [OR] 1.40, 95% confidence interval [CI] 1.15–1.72); adjusted ORs were 2.67 (1.12–6.32) for moderate and 4.68 (1.71–12.78) for high versus low adherence. When MNA item D (psychological stress or acute disease) was neutralized, the categorical association was attenuated (p = 0.071), whereas the per-point association persisted. LVEF was correlated with neither score. Recall-day intake was below the EAR for vitamin D in 98.4%, folate in 86.4%, and calcium in 84.8% of participants. Conclusions: Higher MEDAS scores were associated with better MNA classification in older adults with HFrEF, but neither measure was associated with resting LVEF. Longitudinal studies are needed to establish directionality.