A human adrenergic β3 receptor ligand containing the following 3 components: (A) an unsaturated fatty acid having not less than three double bonds or a pharmaceutically acceptable salt thereof, (B) an unsaturated fatty acid having one or two double bond(s) or a pharmaceutically acceptable salt thereof; and (C) a saturated fatty acid or a pharmaceutically acceptable salt thereof; and a food product and a pharmaceutical containing it, especially, an agent for prophylaxis and/or amelioration of lifestyle-related diseases such as obesity, adipositas, diabetes, hyperlipemia, hypertension and/or gout.