Caldwell Esselstyn is an American physician and author known for his work in preventive medicine and nutrition. He gained prominence for advocating a plant-based diet to prevent and reverse heart disease. Esselstyn's research and clinical practice emphasize the importance of whole foods, particularly fruits, vegetables, whole grains, and legumes, while avoiding animal products and processed foods. He is the author of the book "Prevent and Reverse Heart Disease," which outlines his dietary approach and includes success stories from patients who adopted his recommendations. Esselstyn's work is often associated with the broader movement of plant-based diets and heart health.