Jules Lefèvre

Jules Lefèvre (1863 – May 1944) was a French biochemist and writer who worked on bioenergetics, thermoregulation, and nutrition. His publications included ("Animal Heat and Bioenergetics") and ("Treatise on Bioenergetics"), both published in 1911. He also wrote on vegetarianism, including ("A Scientific Investigation into Vegetarianism"), published in 1904 by the French Vegetarian Society. The book used the term for a diet later described in English as veganism. Lefèvre received several awards for scientific work, including the Laborde Prix, the Montyon Prix, the Petit-d'Ormoy and Mallanet Prix, the Grand Prix Albert de Monaco, and the Legion of Honour.

Education Lefèvre studied at the from 1884 to 1887 and at the National Museum of Natural History, France, from 1887 to 1888. During this period, he earned degrees in mathematics, physics, chemistry, and natural sciences between 1885 and 1887.

Career Lefèvre was appointed agrégé in natural sciences in 1888 and worked as professor of biology at the Lycée du Havre until 1928. He later taught biology in private institutions, including Stanislas and Sainte-Croix. His research on animal energetics began in 1893 and led to more than a hundred communications and forty papers. A 1932 notice stated that his 1911 defined the science of the "animal machine", a term attributed to him. In 1929, he developed this work further in Volume VIII of his ("Treatise on Normal and Pathological Physiology").

Lefèvre's work addressed thermoregulation, heat loss, and thermogenesis in mammals. A 1932 notice stated that he argued that heat production in organisms was both a byproduct of metabolism and a function in maintaining body temperature in homeothermic animals. The same account described his work on the relation between heat loss and ambient temperature, including the increase in heat production as environmental temperature decreases. A revised edition of the book was published in 1919. An authorised English translation by Fred Rothwell was published in 1923 as A Scientific Investigation into Vegetarianism.

The book discusses vegetarianism from historical, physiological, and social perspectives. It gives a history of vegetarian movements and figures including Jean-Antoine Gleizes, then examines nutrition, food composition, and arguments about flesh-eating diets. It also discusses dietary systems including fruitarianism and , and addresses illness, food systems, human energy, nutrition, and thermal regulation in relation to diet.

Recognition Lefèvre received the Laborde Prix in 1894, the Montyon Prix for experimental physiology in 1905, the Pourat Prix in 1908, and the Petit-d'Ormoy and Mallanet Prix in 1913. In 1923, he was designated to receive one of the three rosettes of the Legion of Honour. In 1939, he was awarded the Grand Prix Albert de Monaco, receiving 61 out of 63 votes.

Publications (Paris: French Vegetarian Society, 1904) Chaleur animale et bioénergétique ("Animal heat and bioenergetics"; Paris: Masson, 1911) Traité de Bioénergétique ("Treatise on Bioenergetics"; Paris: Masson, 1911) (translated by Fred Rothwell; London: John Bale, Sons & Danielsson, 1923) Manuel critique de biologie ("Critical Manual of Biology"; Paris: Masson, 1938)