ADIPOCYTE DIFFERENTIATION INHIBITOR, FOOD COMPOSITION FOR INHIBITING ADIPOCYTE DIFFERENTIATION, AND METHOD FOR PRODUCING ADIPOCYTE DIFFERENTIATION INHIBITOR As a novel method for utilizing a Euglena extract, a novel adipocyte differentiation inhibitor, PPARy expression inhibitor, C/EBPa expression inhibitor, food composition for inhibiting adipocyte differentiation, and cosmetic composition for inhibiting adipocyte differentiation are provided. The novel adipocyte differentiation inhibitor, PPARy expression inhibitor, C/EBPa expression inhibitor, food composition for inhibiting adipocyte differentiation, and cosmetic composition for inhibiting adipocyte differentiation each includes an aqueous solvent extract of Euglena as an active ingredient. The aqueous solvent extract of Euglena is, for example, a water extract or hot water extract of Euglena. [FIG. ] 52