After getting his PhD degree in Paris (France), Jean Demarquoy trained as a postdoc at the Institute for Molecular Biology at Baylor College of Medicine in Houston (TX, USA) where he developed gene therapy for citrullinemia. After a second post doc in Paris, he was nominated as an associate professor in 1993 at the Faculty of Science in Dijon (France). He then was nominated as a full professor three years later. Over the last 20 years, he has focused his scientific interest on metabolism and particularly on fatty acid metabolism. He trained dozens of post graduate students including 6 PhD. He worked as an editor for several journals and served as an expert in the French agency for food safety and for several other national and international organizations. He received several awards especially a Lavoisier award in 1989 and 1990.