Adherence to the Mediterranean diet is inversely associated with hematologic inflammatory indices in adults seeking a weight loss dietary program: a cross-sectional study

Background: Low-grade systemic inflammation is a hallmark of excess adiposity and contributes to cardiometabolic risk. Adherence to the Mediterranean diet has been associated with reduced inflammation. However, evidence linking Mediterranean diet to composite inflammatory indices derived from routine blood tests is limited, particularly in individuals seeking weight loss interventions. Methods: In this cross-sectional study, 1,738 adults requesting a weight loss dietary program underwent anthropometric assessment, body composition evaluation, and fasting blood sampling. Adherence to the Mediterranean diet was assessed using the 14-item Mediterranean Diet Adherence Screener (MEDAS). Hematologic inflammatory indices, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation index (SII), lymphocyte-to-monocyte ratio (LMR), systemic inflammation response index (SIRI), and monocyte-to-HDL ratio (MHR), were calculated. Results: After adjustments for sex, age, BMI, body fat percentage, metabolic syndrome, smoking status, physical activity, education level, and marital status, each 1-point increase in MEDAS score was associated with lower NLR (β = - 0.065; 95% CI: - 0.102, - 0.028, p = 0.001), PLR (β = - 2.660; 95% CI: - 4.570, - 0.749, p = 0.006), SII (β = - 21.233; 95% CI: - 31.520, - 10.947, p < 0.001), SIRI (β = - 0.046; 95% CI: - 0.068, - 0.024, p < 0.001), and MHR (β = - 0.0002; 95% CI: - 0.0003, - 0.0001, p = 0.003), and with higher LMR (β = 0.078; 95% CI: 0.038, 0.117, p < 0.001), all reflecting a shift toward a more favorable inflammatory profile. Conclusion: Greater adherence to the Mediterranean diet was associated with a more favorable inflammatory profile. These results support the role of the Mediterranean diet in modulating low-grade systemic inflammation in clinical nutrition settings.