This invention relates to the identification of fatty acid or lipid amides that decrease food intake in mammals, including fatty acid ethanolamides, as ligands for the G-protein coupled receptor OSGPR116, and describes the first demonstration of a specific G-protein coupled receptor that is activated by fatty acid ethanolamides that inhibit feeding. The invention is directed to new methods for screening candidate drugs for their ability to modulate the activity of OSGPR116, and new pharmaceutical agents identified by these methods. It is also directed to the use of such agents in the manufacture of medicaments for the treatment of OSGPR116 mediated diseases, and methods of treating diseases such as obesity and diabetes by administering to an individual a therapeutic amount of a modulator of OSGPR116 identified by these methods.