Kleiber graduated from the Swiss Federal Institute of Technology as an Agricultural Chemist in 1920, earned the ScD degree in 1924, and became a Privatdozent after publishing his thesis, The Energy Concept in the Science of Nutrition.
He also provided the basis for the conclusion that total efficiency of energy utilization is independent of body size.
These concepts and several others fundamental for understanding energy metabolism are discussed in Kleiber's book, The Fire of Life, published in 1961 and subsequently translated into German, Polish, Spanish, and Japanese.
He is credited with the description of the ratio of metabolism to body mass, which became Kleiber's law.
1961: The Fire of Life: An Introduction to Animal Energetics 1954 Guggenheim Fellowship for Natural Sciences (US & Canada), in Molecular and Cellular Biology[4][5]