本文以疾病盛行情形爲基礎的疾病成本法，利用群體歸因風險的概念，除了比較在不同身體質量指數、不同性別及不同年齡之下，罹患代謝症候群疾病的比率及醫療費用之外，更分別以單因子、多因子及組合因子三種方法，在不同的肥胖切點之下，推估肥胖直接成本。研究結果發現：肥胖者罹患心血管疾病之盛行率較高；若分別以BMI=24、27及30爲肥胖切點，則竹東及朴子兩地區所有調查樣本之肥胖直接成本分別爲每年新台幣2,969萬元、1,218萬元及449萬元；平均每個樣本需要負擔的肥胖直接成本，分別約爲每年6,877元，2,821元及1,040元，約爲個人年平均所得的l.74%~0.26%。而以多因子估計法及組合因子估計法估得之肥胖直接成本，則較前述單因子估計法之結果約減少20至50%。

Adopting the approach of cost of illness, this research develops alternative Population Attribution Risk (PAR) models and uses the CVDFACTS and national health insurance data of Taiwan to empirically estimate a prevalence-based medical cost of obesity for samples in Chu-Dong and Pu-Chi townships of Taiwan. The impacts of obesity on metabolic syndrome related coronary heart disease, ischemic heart disease, hypertensive disease, diabetes, hyperlipidemia are studied. Medical expenses of the above mentioned diseases in the national health insurance data are used for estimation. Results indicate (1) The prevalence rates of those obesity related cardiovascular diseases for obese samples are higher than those for normal samples, (2) the estimated yearly costs of obesity for our samples, varied by obesity definitions, are 29,700,000 NT$ (for obesity BMI>24), 12,180,000 NT$ (for obesity=BMI>27) and 4,490,000 NT$ (for obesity=BMI>30) by the proposed single-factor PAR model, (3) the proposed multi-factor (group-factor) PAR model can provide a cost estimate which is about 20% (or 50℃) lower than that from the single-factor PAR model.