Nutrient Clusters Associated with the Dietary Inflammatory Index in Patients with Diabetes and Prediabetes: A Prospective Observational Study

Background/Objectives: The dietary inflammatory index (DII) has been widely used to examine dietary inflammation in chronic diseases; however, the relative contribution of individual nutrients to the total DII score remains unclear. Identifying nutrient clusters that strongly influence the energy-adjusted DII (E-DII) in patients with diabetes and prediabetes may provide practical guidance for dietary counselling and intervention. This study aimed to identify nutrient clusters based on dietary intake and examine their association with the E-DII in patients with diabetes and prediabetes. Methods: In total, 408 dietary records of 17 patients were analysed. The E-DII was calculated from the reported dietary intake using photographs. Exploratory factor analysis was used to derive nutrient clusters, and ordinary logistic regression analysis was applied to examine their association with the E-DII tertiles. Results: Five nutrient clusters (antioxidant-mineral, protein-B complex, fatty acids, plant-lipids, and immune-modulating micronutrients) were extracted, explaining 69.3% of the total variance. Ordinary logistic regression showed that antioxidant-mineral, fatty acids, and immune-modulating micronutrients predicted classification between low, intermediate, and high E-DII groups. Conclusions: Antioxidant-mineral, fatty acids, and immune-modulating micronutrients were associated with a lower probability of belonging to the pro-inflammatory group. The identification of these clusters highlighted specific nutrient combinations that may protect against diet-induced inflammation. These results provided clinically relevant evidence that nutritional strategies emphasising fruits, vegetables, healthy fats, and balanced protein sources may contribute to lowering dietary inflammatory potential and improving metabolic health in patients with diabetes and prediabetes.