PROBLEM TO BE SOLVED: To provide a composition for obesity treatment and prevention and a composition having an antioxidant activity and a method for preparing the same.SOLUTION: The composition comprises a yeast hydrolysate obtained by decomposing yeast with a protease such as KH-15 as an active ingredient and has weight reducing and antioxidant activities.SELECTED DRAWING: Figure 8【課題】肥満治療及び予防用組成物並びに抗酸化活性を有する組成物及びその製造方法を提供する。【解決手段】酵母をKH-15等のタンパク質分解酵素で分解した酵母加水分解物を有効成分として含み、体重減少効果及び抗酸化活性を有する組成物。【選択図】図8