Recent studies have emphasized Body Mass Index (BMI) as a potential indicator for constitutional diagnosis, noting the higher BMI observed in Taeeumin compared to other constitutions. However, 『Donguisusebowon(東醫壽世保元)』 「Sasanginbyeonjeunglon(四象人辨證論)」 have indicated similarities in body shape between Taeeumin and Soeumin, suggesting that physique size alone may not be sufficient for constitutional diagnosis. This study aims to investigate the reasons for this disparity and to reassess the suitability of BMI as a diagnostic indicator for Sasang constitution.
An analysis was conducted to explore the utilization of BMI across eighteen studies focused on body shape for diagnosing constitution. These studies were identified through a search of Korean medicine journals, including the Journal of Sasang Constitutional Medicine. Additionally, the body shape-related items in eleven Questionnaires for Sasang constitution diagnosis were examined. While BMI has been extensively utilized in numerous studies within the field of Sasang constitutional medicine due to its simplicity, its effectiveness is not without limitations. Despite its widespread use, BMI does not fully capture the nuanced concept of body type as delineated in 『Donguisusebowon(東醫壽世保元)』. Moreover, there has been a lack of deliberation regarding whether statistical differences in BMI between constitutions should serve as a definitive criterion for constitutional diagnosis. Ensuring external validity posed challenges in several studies, and the role of BMI was at times exaggerated. Consequently, the reliance on BMI as a constitutional diagnostic indicator presents inherent limitations. Prudent caution should be exercised in utilizing BMI as a major determinant in constitutional diagnosis.