Dr. Mark Hyman is a well-known physician and author specializing in functional medicine, which focuses on identifying and addressing the root causes of diseases. He is the founder and director of the Cleveland Clinic Center for Functional Medicine and has written several best-selling books on health and nutrition. In addition to his medical practice, Dr. Hyman is a prominent speaker and advocate for dietary changes to improve health. He often emphasizes the importance of whole foods and a balanced diet, promoting ideas related to nutrition and wellness in his public appearances and writings.