Herein is reported a fusion polypeptide comprising i) one, two, three or four incretin receptor ligand polypeptides, and ii) one human immunoglobulin Fc-region, wherein at least one of the incretin receptor ligand polypeptides comprises an amino acid that is covalently conjugated to a lipid, and wherein each of the one, two, three or four incretin receptor ligand polypeptides is covalently conjugated by a peptide bond to a terminus of the human immunoglobulin Fc-region, whereby to each terminus of the human immunoglobulin Fc-region only a single incretin receptor ligand polypeptide is conjugated.