With the changing landscape of obesity diagnosis and management and the emergence of more sophisticated tools, major organizations have revisited the role of body mass index as the primary diagnostic metric for obesity. This book, Body Mass Index in Clinical Practice, comes in as a timely resource that provides the readers with cutting-edge information on the measurement and classification of obesity while providing a peek into the future approach to obesity, from metrics to meanings, in the era of AI and LLM-driven personalized interventions. Chapters written by world-renowned scholars in the field of obesity on topical issues with an essential knowledge base relevant to students, researchers, physicians, and allied health care practitioners alike.