The present invention relates to compositions of polyunsaturated omega-3 fatty such as of (5Z,8Z,11Z,14Z,17Z)-eicosa-5,8,11,14,17- pentaenoic acid (EPA) and (4Z,7Z,10Z,13Z,16Z,19Z)-docosa- 4,7,10,13,16,19-hexaenoic acid (DHA) for preventing and/or treating cachexia in a subject. Particularly, the compositions comprise a certain amount of the fatty acids as monoacylglycerides. Further, the compositions of omega-3 fatty acids preferably comprise a certain ratio of the fatty acids as mono-, di- and triacylglycerides as this enhances the digestion and uptake of the EPA and DHA fatty acids. Further, the invention relates to a method of preventing and/or treating cachexia in a subject, including administering a composition of EPA and DHA to the subject, wherein at least a part of the fatty acids are provided in monoacylglyceride form.本發明係關於諸如(5Z,8Z,11Z,14Z,17Z)-二十碳-5,8,11,14,17-五烯酸(EPA)及(4Z,7Z,10Z,13Z,16Z,19Z)-二十二碳-4,7,10,13,16,19-六烯酸(DHA)等多不飽和Ω-3脂肪酸之組合物,其用於預防及/或治療個體之惡病質。特定而言,該等組合物包含某一量之呈單醯甘油形式之脂肪酸。此外,Ω-3脂肪酸之該等組合物較佳包含某一比率之呈單醯甘油、二醯甘油及三醯甘油形式之脂肪酸,此乃因此增強該等EPA及DHA脂肪酸之消化及攝取。此外,本發明係關於預防及/或治療個體之惡病質之方法,其包括向該個體投與EPA及DHA之組合物,其中該等脂肪酸之至少一部分係以單醯甘油形式提供。