The present invention relates to using peroxisome proliferator-activated receptor alpha (PPAR-&alpha) activator for enhancing adipose triglyceride lipase (ATGL) protein expression, in which the enhancement of ATGL expression is achieved by enhancing the ATGL transcription activity by stimulating FoxO1 transposition to enter the cell nucleus. The present invention further relates to a PPAR-&alpha activator for reducing body fat deposition through the PPAR-&alpha/AMPK/FoxO1/ATGL signaling pathway.本發明係關於過氧化體增生活化受體α(PPARα)活化劑增加三酸甘油脂分解酶(Adiopose Triglyceride Lipase,ATGL)蛋白表現,其中該增加ATGL表現是透過刺激FoxO1轉位進入細胞核而增加ATGL的轉錄活性。本發明亦進一步關於PPARα活化劑透過PPAR-α/AMPK/FoxO1/ATGL訊息路徑減少體內脂肪堆積。