Adherence to a Healthy Plant-Based Diet is Associated with Adiposity Indicators in Costa Rican Adults

Abstract Plant-based diets have been associated with favourable health outcomes; however, not all plant-based diets are of the same quality. This study aimed to investigate the associations between three plant-based diet indices: overall plant-based diet index (PDI), healthy plant-based diet index (hPDI), and unhealthy plant-based diet index (uPDI); and measures of adiposity: wrist circumference, waist circumference, waist-to-hip ratio, and BMI. This study used data from 2,027 controls in the Costa Rica Heart Study, a case-control study. A validated food frequency questionnaire was used to create the plant-based diet indices. Multivariable linear regression was used to examine associations between quintiles of the plant-based diet indices and adiposity indicators. Higher hPDI scores were associated with lower adiposity, with waist circumference showing the strongest association. Participants in the highest hPDI quintile had a β= -1.90 cm (95% CI: -3.32, -0.49) lower waist circumference and a β= -0.72 kg/m 2 (95% CI: -1.33, -0.10) lower BMI compared to participants in the lowest quintile. Significant linear trends were observed with waist circumference (P-trend=0.0037), waist-to-hip ratio (P-trend=0.0064), and BMI (P-trend=0.0171). Subjects in the 5 th quintile of the overall PDI had significantly lower waist circumference (β= -1.75 cm (95% CI: -3.14, -0.36)), waist-to-hip ratio (β= -0.010 (95% CI: -0.019, -0.001)), and BMI (β= -0.62 kg/m 2 (95% CI: -1.22, -0.02)). In general, uPDI showed no significant associations with adiposity indicators. Among Costa Rican adults, adherence to hPDI is associated with lower adiposity, whereas uPDI showed no association, indicating the quality of plant-based diets plays a role in body composition.