A study by researchers at the Joslin Diabetes Center has shown that a protein known for its role in inducing bone growth can also help promote the development of brown fat, a "good" fat that helps in the expenditure of energy and plays a role in fighting obesity. "Obesity is occurring at epidemic rates in the U.S. and worldwide and that impacts the risk and prognosis of many diseases," said Yu-Hua Tseng, Ph.D.