Development of a questionnaire-based Dietary Inflammatory Index assessment for clinical implementation

The rising incidence of chronic metabolic diseases places a significant economic burden on healthcare systems. Although the efficacy of lifestyle interventions has been reported, clinical nutrition typically emphasizes total energy and macronutrient intake without consensus on ideal dietary patterns. The Dietary Inflammatory Index (DII) assesses the inflammatory potential of diets and has been linked to diseases like cardiovascular disease, cancer, and type 2 diabetes. However, DII use in clinical practice is limited by its complexity. In this study, we developed a method to calculate DII scores using a clinically available food frequency questionnaire (FFQ). Thirty healthy volunteers provided 3-day dietary records (DR) and completed the FFQ. Dietitians calculated the intake of 29 nutrients from the DR. A created table of nutrient content per FFQ item enabled nutrient intake and DII score calculation from the FFQ. Statistical analysis showed significant correlations between 27 of 29 nutrient intakes and DII scores from the DR and FFQ. Regression equations were developed to predict actual nutrient intakes from the FFQ. The estimated DII (eDII) calculated using the equations correlated strongly with the DR-derived DII (r = 0.716, p<0.0001). With low bias and variance, our method supports individualized and inflammation-targeted dietary interventions.