PROBLEM TO BE SOLVED: To provide a PPAR&gamma activity improver which can prevent or improve diabetes, arteriosclerosis, hypertension, hyperlipidemia, obesity, metabolic syndrome, and further, type 2 diabetes mellitus, visceral fat obesity, and fatty liver by promoting secretion of adipocytokine and improving sugar and lipid metabolism, and to provide an oral composition using a PPAR&gamma activity improver.SOLUTION: The invention provides a PPAR&gamma activity improver containing legume plant extracts and Lamiaceae plant extracts, and an oral composition using the PPAR&gamma activity improver.