Methods of treating metabolic diseases and disorders using a composition comprising an antigen binding protein specific for the GIPR polypeptide conjugated to a GLP-1 receptor agonist are provided. In various embodiments the metabolic disease or disorder is type 2 diabetes, obesity, dyslipidemia, elevated glucose levels, elevated insulin levels and diabetic nephropathy. In certain embodiments the composition comprises an antibody or functional fragment thereof comprising a cysteine at one or more conjugation site(s) wherein the GLP-1 receptor agonist is conjugated to the antibody or functional fragment thereof through the side-chain of the cysteine residue.