Associations between adherence to plant-based diets and osteoporosis and visceral fat area in middle-aged adults: evidence of a large population-based study.

Objectives: Although plant-based diets (PBDs) are widely recognized for their cardiovascular benefits, their results on bone remain controversial. This study aimed to assess the association of PBDs with osteoporosis and fat indices in middle-aged adults. Methods: This analysis included 9,295 adults from the Ravanser Non-Communicable Disease (RaNCD) cohort. Nutritional information was collected through a validated food frequency questionnaire (FFQ), which was used to derive overall, healthy, and unhealthy PBD indices. Participants underwent the bioelectrical impedance analysis (BIA) to measure body fat (BF), fat mass index (FMI), and visceral fat area (VFA). Results: The highest tertile of healthy PBD was not associated with the odds of osteoporosis than the lowest tertile (OR for men: 1.07; 95%CI: 0.66-1.74 & OR for women: 1.24; 95%CI: 0.79-1.94). However, it was associated with a lower VFA (6.01 cm² for men and 13.64 cm² for women) than the lowest tertile. The highest tertile of overall and unhealthy PBDs was not associated with the odds of osteoporosis in men and women, while they were associated with a higher VFA [(3.22 cm² for men and 4.80 cm² for women) & (3.22 cm² for men and 11.78 cm² for women)] than the lowest tertile, respectively. A significant association was between PBD indices and BF and FMI in both sexes. Conclusions: These findings suggest that while only healthy PBDs may contribute to improved fat distribution, they do not appear to influence osteoporosis risk. Longitudinal studies are needed to explore the long-term outcome of adherence to PBDs on bone.