Book excerpt: Lifestyle medicine is the use of lifestyle behaviors to prevent, treat, and manage chronic disease. A particularly important aspect of lifestyle medicine is the use of an evidence-based approach to inform and guide lifestyle behavior strategies. The purpose of Lifestyle Medicine for Chronic Diseases is to provide foundational knowledge at an introductory level to those interested in using lifestyle therapeutics in the treatment plan of individuals with chronic diseases. The most up-to-date information on the core elements of lifestyle therapeutics are presented and applied to chronic diseases in an evidence-based approach. The Lifestyle Medicine Toolbox at the end of the text provides practical tools that can be used when implementing lifestyle strategies.