Plant-based diets (PBDs) have gained a positive reputation among experts as a solution to combat the epidemic of MetS.

A total of 2225 healthy Iranian individuals aged 35–70 years were considered eligible to be included in this cross-sectional investigation. Various dietary, anthropometric, and biochemical assessments were conducted using standard, valid methods/tools. Relevant PBD scores were calculated using three a posteriori indices, including the overall plant-based diet index (PDI), healthful PDI (hPDI), and unhealthful PDI (uPDI).

Our findings showed that women with the highest adherence to hPDI had a lower chance of MetS. Also, participants in the top tertiles of hPDI were more likely to have a lower risk of low serum HDL-c and abnormal glucose homeostasis. Additionally, a significant increasing trend was observed for low serum HDL-c across tertiles of uPDI.

Our observations suggest that healthful-rich plant foods may have a protective effect against MetS, especially in women.