Introduction: Traditional Chinese medicine (TCM) theory believes that diet is very important in changing body constitution and preventing diseases because food is similar to medicine. This study aimed to explore the effects of obesity-related parameters and dietary habits on TCM body constitution in Taiwanese people. Methods: This study applied an observational cross-sectional design. Individuals were selected from the Taiwan Biobank Research Database. The body constitution questionnaire (BCQ) and food frequency questionnaire (FFQ) were administered. Yin deficiency, yang deficiency, and stasis in TCM were assessed by BCQ. Obesity-related parameters were defined as body weight, body fat, and body mass index (BMI). Multiple linear regression and mediation analyses were conducted. Results: A total of 16,790 individuals were enrolled in the study. Individuals with higher FFQ scores and BMI had better yang deficiency, yin deficiency, and stasis patterns. Those with higher body weight and body fat had poor yang deficiency, yin deficiency, and stasis patterns. After adjusting for potential confounders, all obesity-related parameters partially mediated the association between the FFQ and yang deficiency or stasis patterns. Only body weight partially mediated the association between the FFQ and yin deficiency patterns. Conclusion: Dietary habits and obesity-related parameters have direct effects on TCM body constitutions. Healthy dietary habits have an indirect effect on TCM body constitutions through obesity-related parameters, especially for yang deficiency and stasis patterns. Further studies are needed to confirm and understand the potential mechanisms, including innate physiological and environmental factors, underlying these findings.
