Positive association of unhealthy plant-based diets with the incidence of abdominal obesity: comparison of baseline, most recent, and cumulative average diets

Document Type

Journal Article

Publication Date



Epidemiology and health




Plant-based diet index; abdominal obesity incidence; prospective cohort study; unhealthy plant foods; waist circumference


Objectives: Different approaches using repeated dietary measurements may yield differences in the magnitude and interpretation of findings. We aimed to compare three dietary measurements (baseline, most recent, and cumulative average) in the association between plant-based diet indices (PDIs) and incident abdominal obesity in Korean adults aged 40-69 years. Methods: This study included 6054 participants (women, 54%) free of abdominal obesity at baseline, defined as waist circumference ≥ 90 cm for men and ≥ 85 cm for women. As exposures, baseline, most recent, and cumulative average for PDI, healthy-PDI (hPDI), and unhealthy-PDI (uPDI) were created. A Cox proportional hazard model was used to estimate the hazard ratios (HRs) for abdominal obesity. Results: During 45,818 person-years of follow-up (median 9 years), we identified 1778 incident cases of abdominal obesity. In multivariable-adjusted analysis, a higher uPDI was associated with an increased risk of abdominal obesity in both total and stratified analyses. The findings were consistent across all approaches (Q5 vs. Q1, HR baseline=1.70, 95% CI 1.46, 1.98; HR most recent=1.52, 95% CI 1.30, 1.78; HR cumulative average=1.76, 95% CI 1.51, 2.06 in total set). PDI showed no meaningful association with abdominal obesity risk in all analyses. hPDI average had a suggestive inverse association with abdominal obesity risk in men and hPDI baseline had a positive association with abdominal obesity risk in women. Conclusion: Greater adherence to unhealthy plant-based diets may increase the risk of developing abdominal obesity in Korean adults. The findings were generally consistent across all approaches.


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