"Fletcherism: What It Is; Or, How I Became Young at Sixty" by Horace Fletcher is a health and nutrition guide written in the early 20th century. This work explores the principles of "Fletcherism," a dietary philosophy emphasizing the importance of thorough mastication (chewing) to improve digestion and overall health. The author shares his personal journey from poor health in his forties to a revitalizing transformation through his nutritional practices, which he believes can benefit anyone seeking a healthier and happier life. At the start of the book, Fletcher details his struggles with health issues at age forty, including obesity and frequent illnesses, and how these challenges led him on a quest for better nutrition. He recounts the moment he decided to change his lifestyle after being declined for life insurance, realizing he needed to understand and correct his dietary habits. Drawing inspiration from various sources, including philosophical insights on eating and digestion, Fletcher introduces the Five Principles of Fletcherism: waiting for a true appetite, eating what appeals most, extracting maximum taste, enjoying the experience, and trusting nature to guide nutritional needs. His narrative sets the stage for a broader exploration of how careful eating can lead to better health and longevity. (This is an automatically generated summary.)