Food inflammation index reveals the key inflammatory components in foods and heterogeneity within food groups: How do we choose food?

INTRODUCTION: Food is a critical factor of chronic inflammation. Few studies tried to quantize inflammatory effects of food. Moreover, the discrepancies in inflammatory effects among foods within the same food group are frequently ignored. OBJECTIVES: This study aimed to compare inflammatory effects of food based on Food Composition Tables via a Food Inflammation Index (FII). We aimed to reveal heterogeneity within food groups in dietary guidelines and identify the key components. METHODS: The FII was adapted from Dietary Inflammation Index (DII) with a weighted algorithm, validated by NHANES.The Food Inflammation Scores of Individuals (FISI) of various dietary patterns were analyzed and compared. FII scores were converted to percentages for intuitive grading using the United States Department of Agriculture Food Composition Table (USDA-FCT), and China-FCT was also used for validation.The FII scores of various food groups based on USDA-FCT and dietary guidelines were counted and compared to reveal the heterogeneity within food groups. RESULTS: FII proves effective in delineating food inflammatory effects. It reveals substantial inflammatory risk even with adherence to the Mediterranean diet, highlighting the need to address intra-group heterogeneity. Within USDA-FCT, nuts and select vegetable oils (rich in flavonoids and n-3 polyunsaturated fatty acids) are notable anti-inflammatory foods, contrasting with pro-inflammatory meats high in saturated fats. According to the current dietary nutrition guidelines, the inflammatory effects of food groups vary greatly. Further subdivision of food groups can weaken the problem of heterogeneity within food groups, thereby providing more accurate dietary recommendations. CONCLUSION: Quantifying the inflammatory effects of whole foods is important for general consumers to realize their own dietary inflammatory exposure risk. The FII reveals the heterogeneity within food groups and can be a reference for dietary recommendations. This public tool could be beneficial for consumer choice, dietary guideline revision, science research for healthier eating.