The present invention provides a method of determining a modulator of Y receptor associated bone remodeling and/or bone growth and/or adiposity in a human or animal subject. The present invention further provides a method of determining a modulator of Y receptor associated differentiation of a mesenchymal stem cell into an osteoblast or an adipocyte. The present invention further provides method for the treatment of bone disorders, and in particular osteoporosis, and obesity in addition to compositions for the treatment of said disorders.