Otto Warburg (1883-1970) obtained is doctorate of chemistry in 1906 which was followed by a medical degree in 1911. He was awarded the Nobel Prize for medicine and physiology in 1931. Much of his work involved photosynthesis, metabolism of cancer cells and the chemistry of enzymes involved in energy transfer within cells. An extensive biography was written by Hans Kreb, a colleague who was a co-discoverer of the Krebs cycle.
His work is sometimes used to justify ketogenic diets,