The present invention relates to the field of metabolic research. Metabolic disorders, such as obesity, are a public health problem that is serious and widespread. GMG-3, GMG-4, Cluster 1, GMG-6A, or GMG-6B polypeptides have been identified that are beneficial in the treatment of metabolic disorders. These compounds should be effective for reducing body mass and for treating metabolic-related diseases and disorders. These metabolic-related diseases and disorders include hyperlipidemias, atherosclerosis, diabetes, and hypertension.