Brian Fertig, M.D., F.A.C.E., is the Founder and President of the Diabetes & Osteoporosis Center in Piscataway, New Jersey, established in 1994. Dr. Fertig's experience in diabetes, endocrinology and metabolism, including internship, residency, fellowship, and private practice, spans a period of 34 years.His passion for patient care and for finding the root problems of disease was his motivation and purpose for writing a 2 volume comprehensive book on metabolism, called "Metabolism & Medicine." On his exploratory journey, Dr. Fertig discovered modern conceptual tools to improve the problem-solving skill sets of great utility for him, his practitioner colleagues, and the next generation of healthcare providers. His genuine concern for the future of medical student education is one of the main factors that motivated him to write this book.Volumes I and II of Metabolism & Medicine examine chronic diseases of aging through the lens of metabolism and what causes things to go awry in the context of aging and human behavior. It additionally introduces a new model of patient care called the "Physiological Fitness Landscape" that predicts the onset of chronic disease.