The present invention relates to a composition comprising GRIM-19 protein as an active ingredient for preventing or treating obesity or lipid-related metabolic diseases. More particularly, the present invention relates to a composition for preventing or treating obesity or lipid-related metabolic diseases wherein the composition comprises GRIM-19 protein as an active ingredient for preventing or treating metabolic diseases caused by immune response disorders or interactions between genetic, metabolic, or environmental complex factors. The GRIM-19 protein according to the present invention exhibits excellent effectiveness not only in reducing lipocytes and total cholesterol content in the body, but also in suppressing the differentiation of cytotoxic Th17 cells that produce and secrete inflammatory cytokines. Also, GRIM-19 has been found to have excellent effectiveness in regulating a STAT3 mediated inflammatory response in an inflammatory environment related to obesity. Thus, the present invention can be used for preparing a treatment agent and a functional food that can effectively treat obesity or lipid-related metabolic diseases.
