John Harvey Kellogg, American surgeon, co-created Corn flakes (d. 1943)
John Harvey Kellogg (February 26, 1852 – December 14, 1943) was an American medical doctor, nutritionist, inventor, health activist, eugenicist, and businessman. He was the director of the Battle Creek Sanitarium in Battle Creek, Michigan. The sanitarium was founded by members of the Seventh-day Adventist Church. It combined aspects of a European spa, a hydrotherapy institution, a hospital and a high-class hotel. Kellogg treated the rich and famous, as well as the poor who could not afford other hospitals.

Disagreements with other members of the church led to a major schism within the denomination: Kellogg was disfellowshipped in 1907, but continued to follow many Adventist beliefs and directed the sanitarium until his death in 1943. Kellogg also helped to establish the American Medical Missionary College in 1895. The college operated independently until 1910, when it merged with Illinois State University.

Kellogg was a major leader in progressive health reform, particularly in the second phase of the clean living movement.

He wrote extensively on science and health. His approach to "biologic living" combined scientific knowledge with Adventist beliefs, promoting health reform, and temperance. His promotion of developing anaphrodisiac foods was based on these beliefs. Many of the vegetarian foods that Kellogg developed and offered his patients were publicly marketed: Kellogg is best known today for the invention of the breakfast cereal corn flakes, originally intended to be an anaphrodisiac, made by his brother, Will Keith Kellogg. His creation of the modern breakfast cereal changed "the American breakfast landscape forever."As an early proponent of the germ theory of disease, Kellogg was well ahead of his time in relating intestinal flora and the presence of bacteria in the intestines to health and disease. The sanitarium approached treatment in a holistic manner, actively promoting vegetarianism, nutrition, the use of enemas to clear "intestinal flora", exercise, sun-bathing, and hydrotherapy, as well as the abstention from smoking tobacco, drinking alcoholic beverages, and sexual activity.

Kellogg dedicated the last 30 years of his life to promoting eugenics. He co-founded the Race Betterment Foundation, co-organized several National Conferences on Race Betterment and attempted to create a 'eugenics registry'. Alongside discouraging 'racial mixing', Kellogg was in favor of sterilizing 'mentally defective persons', promoting a eugenics agenda while working on the Michigan Board of Health and helping to enact authorization to sterilize those deemed 'mentally defective' into state laws during his tenure.