A method to suppress obesity, comprising administering to a subject in need thereof an effective amount of a composition comprising the following components (A) and (B): (A) oleuropein; and (B) a sulforaphane compound, wherein the amount of component (A) alone contained in the composition does not result in a fat accumulation-suppressing effect, and the amount of component (B) alone contained in the composition does not result in a fat accumulation-suppressing effect.