The present invention relates to a pharmaceutical and food composition for treating, preventing, or alleviating a metabolic disease, containing, as an active ingredient, extracellular vesicles derived from Akkermansia muciniphila. The composition of the present invention can be used as a pharmaceutical/food composition and the like for treating, preventing, or alleviating metabolic diseases, in particular metabolic diseases such as obesity, diabetes, hyperlipidemia, arteriosclerosis, and hypertension, occurring or exacerbated due to a high fat diet. In addition, in the present invention, a fermented food itself, prepared by adding Akkermansia muciniphila, can be used for the purpose of preventing or alleviating a metabolic disease occurring or exacerbated due to a high fat diet.