A groundbreaking program to help you sleep faster and better from the bestselling author of The FastDiet, revised and updated with bonus material on brain health, mood, immunity, and metabolism.

We know a good night’s sleep is essential for a healthy brain and body. But sleep problems are sadly all too common. So why do so many of us struggle to sleep well? In Four Weeks to Better Sleep, Dr Michael Mosley explains what happens when we sleep, what triggers common sleep problems, and why standard advice rarely works.

Prone to insomnia, Mosley took part in numerous sleep experiments and tested every remedy. The result of his research is a radical four-week plan, based on the latest science, designed to help you re-establish a healthy sleep pattern in record time.

With surprising recommendations—including tips for teenagers, people working night shifts, and those prone to jet lag—plus recipes that will boost deep sleep by improving your gut microbiome, Four Weeks to Better Sleep provides the tools you need to reduce stress and feel happier. An indispensable program, it will not only get you to sleep faster but improve the quality of your sleep, so you wake rested and refreshed.

*Previously published as Fast Asleep (2020), this expanded edition features new science from the author’s 2022 BBC Horizon documentary; the results of his own successful sleep experiments; “10 Thing You Can Change With Better Sleep”; and a detailed four-week plan with easy-to-follow tips, exercises, and delicious gut-friendly recipes.*

About The Author

Photograph by David Bostock

Dr Michael Mosley

Dr. Michael Mosley (1957–2024) was the #1 New York Times bestselling author of The FastDiet, FastExercise, FastLife, The 8-Week Blood Sugar Diet, The Clever Gut Diet, and The Fast800 Diet among others. Dr. Mosley trained to be a doctor at the Royal Free Hospital in London before joining the BBC, where he spent three decades as a science journalist and executive producer. Following his time at the BBC, he was a well-known television personality and won numerous television awards, including an RTS (Royal Television Award), and was named Medical Journalist of the Year by the British Medical Association.

Product Details

Publisher: Atria Books (January 13, 2026)
Length: 336 pages
ISBN13: 9781668217993

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Raves and Reviews

“A brilliantly informative book showing you how to boost your sleep and cure insomnia.”

– Daily Mail (London)

“Mosley’s first-hand experience of insomnia, and his search for answers, makes this book a real page turner. It will change many lives.”

– Prof. Barry Marshall, winner of the Nobel Prize for Medicine

“I read this eagerly because I am desperate for tips on how to sleep better. It is based around the revolutionary idea that when it comes to sleep what matters is not the hours you spend in bed but the quality of the sleep you are getting—your sleep efficiency. This book was full of surprises!”

– Jeremy Vine, BBC Radio 2 presenter and broadcast journalist

“A fascinating and accessible book with some truly surprising findings. If you or someone you know struggles with poor sleep, this book is a must.”

– Prof. Felice Jacka, director of the Food & Mood Centre at Deakin University

“This book is well written, well researched and very practical. It’s a down to earth guide to sleeping better written by a famous former insomniac. It covers the latest science and offers fascinating insights and many original tips.”

– Dr. Tim Spector, professor of genetics at Kings College, London

“I would highly recommend Fast Asleep as it is engaging, humorous, and a very relaxing read with practical advice on understanding every aspect of sleep and our friendly gut bacteria. Also full of very useful tips for parents.”

– Dr. Desiree Silva, professor of pediatrics at the University of Western Australia

“What a great book! The subject is fascinating and Dr. Michael Mosley has produced a clear and very entertaining guide to the dark mysteries of sleep and how to sleep your way to better health.”

– Dr. Roy Taylor, professor of medicine and metabolism at the University of Newcastle