Michael studied philosophy, politics and economics at the University of Oxford and then became an investment banker, before retraining as a doctor at the Royal Free Hospital in London. After graduating from medical school and becoming disillusioned by psychiatry, he joined the BBC as a trainee assistant producer in 1985.

Over the next 25 years, Michael made numerous science and history documentaries initially working behind the camera and more recently as a presenter. As a presenter, he has made numerous series for the BBC, including Medical Mavericks, Blood and Guts, Inside Michael Mosley, Science Story, Eat, Fast & Live Longer and others.

Following the success of Eat, Fast & Live Longer, Michael co-authored his first book called The Fast Diet in 2013. He went on to become a #1 New York Times bestselling author of many books including Fast Exercise, FastLife, The 8-Week Blood Sugar Diet, The Clever Gut Diet, The Fast 800 Diet, and Covid-19.

In 2020, Michael presented the documentary series The Diagnostic Detectives. In the series, each episode is centred around a group of doctors tackling a patient's problem.

Michael lives in Buckinghamshire with his wife Clare, a GP, and has four children.