Kellyann Petrucci, M.S., N.D., is the author of the New York Times bestselling book Dr. Kellyann’s Bone Broth Diet (Rodale, 2015). She also is host of the PBS special, 21 Days to a Slimmer, Younger You. A weight-loss and natural anti-aging transformation expert, Dr. Petrucci has a private practice in the Birmingham, Michigan area and is a concierge doctor for celebrities in New York City and Los Angeles. She is a board-certified naturopathic physician and a certified nutrition consultant. Dr. Petrucci is a regular guest on television shows including The Doctors, Dr. Oz, and national news programs, and has authored six books for John Wiley & Sons. In addition, she is a regular contributor to The Huffington Post and MindBodyGreen. She is the driving force behind the popular website drkellyann.com. Dr. Petrucci did postgraduate work in Europe, studying naturopathic medicine in England and Switzerland. She is one of the few practitioners in the United States certified in biological medicine by the esteemed Dr. Thomas Rau of the Paracelsus Klinik Lustmuhle in Switzerland.