The study measured fat mass, body water compartments, and bone mineralizing in people with PWS and compared them with a control group with nonsyndromal obesity matched for gender and bone age. Criteria for participants with PWS were that they were assessed and diagnosed according to the Holm Criteria, which is a list of major and minor criteria for diagnosing the syndrome. None of these participants were receiving hormone therapy. Control participants were matched by gender and age and were to have no endocrine causes of obesity.