John Harvey Kellogg (1852-1943) was an American medical doctor in Battle Creek, Michigan, who ran a sanitarium using holistic methods, with a particular focus on nutrition, enemas and exercise. Kellogg was an advocate of vegetarianism and is best known for the invention of the corn flakes breakfast cereal with his brother, Will Keith Kellogg. Kellogg also patented a process for making peanut butter.