The present invention relates to the field of obesity research. Obesity is a public health problem that is serious and widespread. A compound, homotrimer of GMG-2 polypeptide fragment comprising globular domain and all or part of GMG-2 collagen-like region, has been identified that has utility for reducing body mass, for maintaining weight loss, and for treating obesity-related diseases and disorders. These obesity-related diseases and disorders include hyperlipidemias, atherosclerosis, diabetes, and hypertension.