The exuberant medical broadcaster who popularised the 5:2 diet

MICHAEL MOSLEY: 1957 - 2024

Dr Michael Mosley, who has died in Greece aged 67, was a Tiggerish presenter of television science documentaries, and became one of Britain’s leading communicators on diet and healthy living.

Mosley was a television producer for some two decades before he began to appear in front of the camera in his 50s. Billed as Dr Michael Mosley – he had trained, though never practised, as a psychiatrist – he proved a television natural, combining professorial good looks with boyish enthusiasm.

Dr Michael Mosley was one of Britain’s leading communicators on diet and healthy living.

Mosley’s approach was evidence-based; as well as highlighting relevant scientific studies, he was happy to use himself as a guinea pig, not only to test a hypothesis but also to enliven potentially dry subject matter. One journalist called him “the great gonzo scientist of our times”.

For the 2014 BBC documentary Infested! Living with Parasites, he travelled to a backstreet abattoir in Nairobi to secure beef riddled with Taenia saginata cysts. After eating it, he later ingested a tiny camera to let viewers observe the metre-long tapeworm that had developed inside him.

He also experimented on camera with the magic-mushroom drug psilocybin in a laboratory (“like going into hyperdrive on Star Trek”) and ate black pudding made from his own blood. Some of his ideas had to be abandoned at the behest of his wife, Clare, who vetoed, for example, “the idea of infesting myself with pubic lice”.

Dr Michael Mosley when he turned his attention to sleep health.

Mosley rejected the suggestion that such programmes were gimmicky – “generally speaking, everything I do has a substantial basis to it” – and cited George Orwell as his inspiration: “He lived his journalism in Down and Out in Paris and London and The Road to Wigan Pier. He put himself out there. It’s Orwell who put me on the road to this.”

Mosley also tried various diets for his programmes and in 2012 presented Eat, Fast and Live Longer, a documentary in the BBC’s Horizon strand, in which he explored the efficacy of intermittent fasting.

Dr Michael Mosley and wife Dr Clare Bailey.

In an accompanying article in the Telegraph, Mosley revealed that “after a final slap-up dinner of steak”, he had experimented with eating no food for four days: “I was convinced that hunger would build day by day, getting steadily worse until finally I gave in and raided a local bakery.

“But what I found was that, after the first 24 hours, things got better. I had hunger pangs, but they passed.” He lost more than 900 grams of body fat and his blood glucose levels plummeted.

Drawing on the work of professional nutritionists such as Krista Varady and Michelle Harvie, Mosley explained in his article that he had devised a less dramatic alternative called the 5:2 diet: “With this regimen, you eat what you want five days a week, then twice a week you restrict yourself to just 600 calories.” After six weeks, he had lost more than six kilograms.

Mosley’s findings drew such an eager response – his Telegraph piece rapidly secured nearly a million online hits – that the following year, he published his first book, The Fast Diet (with Mimi Spencer). Within a few months, it was reprinted 13 times and sold more than 350,000 copies. He went on to write or co-author several more bestselling books, including Fast Exercise and The Clever Guts Diet.

Mosley was inspired to lose weight after his father contracted diabetes, followed by dementia, then death at the age of 74; he knew of no male in his family who had reached 75. He was convinced that his diet had put his own Type 2 diabetes into “remission”.

Later, he devised the Fast 800 Diet, which required its practitioners to restrict themselves to an 800-calorie, low-carbohydrate, “Mediterranean” diet for eight weeks at a time. Celebrity enthusiasts for his diets were reported to include Beyonce, Hugh Jackman and Benedict Cumberbatch.

BBC television presenter Michael Mosley during lunch with Age journalist Kerrie O’Brien at Kisume in Melbourne, 2017.Credit: Fairfax

The former Labour deputy leader Tom Watson (Lord Watson of Wyre Forest) credited one of Mosley’s books with helping him to lose 44 kilograms and “reverse” his Type 2 diabetes.

In 2021, Mosley came in for some criticism for his Channel Four series Lose a Stone in 21 Days with Michael Mosley, with a spokesperson for the eating disorder charity Beat saying: “It is incredibly worrying to see a national programme yet again promoting extreme weight loss and crash dieting. The promise inherent in the title is likely to attract people suffering from or vulnerable to eating disorders.”

The presenter always emphasised, however, that people should consult their doctor before making any significant change in their diets.

Nevertheless, as he became ubiquitous on television magazine programmes and was the resident medic on The One Show, Mosley admitted to a degree of worry about the influence he wielded over the nation’s eating habits. “What happens if someone loses too much weight and makes themselves ill?” he reflected, but concluded: “Nobody has ever come up to me and said, ‘you utter bastard, you’ve ruined my life’ – and my work is utterly rooted in science.”

Michael Mosley was born in Calcutta on March 22, 1957; his father was a banker, while his grandfather on his mother’s side was an Anglican bishop. Michael was “quite religious until I was about 20” and contemplated becoming a priest: “I spent a while on Iona and [in] other Christian communities. I was searching for God, then I didn’t find God – or at least God didn’t find me.”

After reading PPE (Philosophy, Politics and Economics) at New College, Oxford, he went into the city, but banking palled after two years and he enrolled in a graduate training scheme at the Royal Free Hospital Medical School. On his first day in A&E, he recalled, he stitched his glove to his first patient’s head.

He hoped to specialise in psychiatry but became disillusioned by “how little could really be done for people with mental illness”, and toyed with joining the BBC’s producer training scheme.

“I discussed it with people in the media before I jumped. And they all said: ‘No, no, don’t do it. It’s a terrible thing to go into, you should stick with the noble art of medicine.’ And most of the medics said: ‘Go, go. It sounds much more fun.’ So … I thought I would do it for a year or two and see if it suited me, and I found that it did.”

Michael Mosley at the ICC Sydney, 2019.Credit: Brook Mitchell

He started out on the children’s series Investigating Science and graduated to producing episodes of Tomorrow’s World, QED and Dr Phil Hammond’s Trust Me, I’m a Doctor, uncovering healthcare scandals, as well as Sir John Harvey-Jones’ business series Troubleshooter and the evocative 2003 drama-documentary, Pompeii: The Last Day.

In 1994, he wrote and produced Ulcer Wars, a Horizon documentary promoting the physician Barry Marshall’s then-novel theory that a bacterium could cause gastric ulcers.

He was named Medical Journalist of the Year by the British Medical Association and received some 20,000 letters from people whose seemingly incurable stomach pains disappeared after they started taking antibiotics. “I probably did, in a funny way, more good with that one program than if I had stayed in medicine for 30 years,” he said in 2004.

In 2007, he devised a BBC TV series called Medical Mavericks, and, unable to find a suitable host, agreed to present it himself. The Telegraph’s James Walton praised the tyro broadcaster’s “sharp eye for memorable anecdotes” and “winning enthusiasm for his subject”, plus his willingness to “re-enact a few of the experiments himself, with nitrous oxide inducing an impressive fit of the giggles as he tried to describe its effects”. In 2013, he took on presenting duties in a revived Trust Me, I’m a Doctor, focusing on lifestyle and preventative medicine.

Barnaby Joyce on Australia’s Sleep Revolution with Dr Michael Moseley.

Mosley suffered from insomnia, which inspired his 2020 book Fast Asleep; in the same year, he published a book on COVID-19 and the race to find a vaccine. From 2021, he presented the popular Radio 4 series Just One Thing, in which he advised listeners on how they could make small positive changes to their lives, from eating more slowly to walking backwards and being kind (which may help to reduce inflammation).

He had a benign and soothing broadcasting voice, with a slight lisp, and in a special run of nightly episodes, he took the audience on a “sonic journey” that explored relaxation techniques including slow, deep breathing: these were so effective that listeners might be fast asleep before the end of the programme.

Speaking of the diet regime with which he will forever be associated, Mosley admitted latterly that he had become more of a 6:1 than a 5:2 dieter, drank red wine five nights a week, and was a chocolate fiend: “I have even been known to steal my daughter’s Easter eggs and have to replace them.”

“You can tell that riches have not gone to his head,” observed Harry Wallop in a Telegraph interview, noting his “frayed collar, battered pair of trousers and scuffed shoes”. “Though he enjoys the ‘showboating’ aspect of presenting television programmes, for him the joy is in influencing the scientific debate, not being on the front cover of Radio Times.”

Mosley had gone for a walk on the Greek island of Symi last Wednesday afternoon when he was reported missing. After a four-day search, his body was found on rocky terrain.

He married, in 1987, Clare Bailey, who became a GP; she survives him with their daughter and three sons.

The Telegraph, London