The Role of Whole Food Plant-Based Food Intake on Postprandial Glycemia in Type 1 Diabetes

Abstract Background Whole food plant-based diet (WFPBD), minimally processed foods with limited consumption of animal products, is associated with improved health outcomes. The benefits of WFPBD are underexplored in individuals with type 1 diabetes (T1D). The primary objective of this analysis is to evaluate the association between WFPBD on glycemia in individuals with T1D. Research Design and Methods Utilizing prospectively collected meal events from the Type 1 Diabetes Exercise Initiative, we examined the effect of WFPBD intake on glycemia, determined by the Plant-Based Diet Index (PDI). The PDI calculates overall, healthful (hPDI), and unhealthy PDI (uPDI) to evaluate for degree of processed foods and animal products (i.e. WFPBD). Mixed effects linear regression model assessed time-in-range (TIR), time-above-range, and time-below-range. Results We analyzed 7,938 meals from 367 participants. TIR improved with increasing hPDI scores, conferring a 4% improvement in TIR between highest and lowest hPDI scores (high hPDI:75%, low hPDI:71%; p<0.001). Compared to meals with low hPDI, meals with high hPDI had lower glucose excursion (high hPDI:53mg/dL, low hPDI:62mg/dL; p<0.001) and less time >250mg/dL (high hPDI:8%, low hPDI:14%; p<0.001). These effects were present but less pronounced by PDI (high PDI:74%, low PDI:71%; p=0.01). No differences in time below 70mg/dL and 54mg/dL were observed by PDI or hPDI. Conclusions Meal events with higher hPDI were associated with 4% postprandial TIR improvement. These benefits were seen primarily in WFPBD meals (captured by hPDI) and less pronounced plant-based meals (captured by PDI), emphasizing the benefit of increasing unprocessed food intake over limiting animal products alone.