It’s one of Hollywood’s favourite diets, heralded by a legion of toned A-list fans including Jennifer Aniston and Mark Wahlberg.
But now, to the dread of dietitians across the planet, there’s an even more extreme version of ‘intermittent fasting’ being taken up by those wanting to lose weight — the OMAD diet.
An abbreviation for ‘one meal a day’, the trend does exactly what it says on the tin.
Coldplay frontman Chris Martin swears by it after learning of the diet from legendary rocker Bruce Springsteen, whose wife is a proponent and spoke about it over lunch.
Yet they are not the only famous faces who get by on just one meal a day.
Coldplay frontman Chris Martin swears by it after learning of the trick directly from legendary rocker Bruce Springsteen, whose wife passed on the physique-boosting hack over a lunch. Pictured above, filming the Graham Norton Show in 2019
Chris Martin (before, left; after right) has had a stark weightloss transformation in recent years
Coldplay’s Chris Martin revealed last month: ‘I stop eating at 4[pm] and I learned that from having lunch with Bruce Spingsteen’. Pictured above, svelte Springsteen performing in 2014 at the New Orleans Jazz & Heritage Festival
Rishi Sunak is himself a follower the brutal one meal a day diet, the Daily Mail’s Richard Eden revealed this week. Pictured above, leaving Downing Street to attend the House of Commons in March
In an interview with the Evening Standard yesterday, Gary Lineker, 62, also disclosed he ‘only really eats one major meal a day’
For, as the Daily Mail’s Richard Eden exclusively revealed this week, the lean Rishi Sunak is himself a follower the brutal diet – or at least does so once a week.
The Prime Minister’s mother-in-law, Sudha Murty, 72, revealed her family have long observed a fast every Thursday, in comments recorded at a talk in India and now posted on social media.
‘When my daughter told my son-in-law about our family tradition — he didn’t know anything about [it] or the guru we fast for,’ she said.
But he speedily acquiesced. She added. ‘He told my daughter, “OK, Thursday is a good day”,’ and on that day he eats only one meal.’
Q+A: Everything you need to know about intermittent fasting
How does it work?
Intermittent fasting involves switching between days of fasting and days of eating normally.
It generally falls into two categories – narrowing eating times to 6-8 hours per day, also known as the 16:8 diet, and 5:2 intermittent fasting.
The 16:8 diet is a form of intermittent fasting, also known as Time Restricted Eating.
But the ‘one meal per day’ – or OMAD – has also picked up mass appeal among men in recent years, as an efficient way to cut weight, especially this time of the year when many are trying to get in shape for summer.
The one meal eaten on the OMAD diet is usually consumed around dinner time.
What is the difference between time restricted eating and 5:2 intermittent fasting?
Followers of the 16:8 eating plan fast for 16 hours a day, and eat whatever they want in the remaining eight hours – typically between 10am and 6pm.
This may be more tolerable than the well-known 5:2 diet – where followers restrict their calories to 500-to-600 a day for two days a week and then eat as normal for the remaining five days.
What are the drawbacks of intermittent fasting?
Drawbacks of the fasting plan may be that people overindulge in the hours they can eat, leading to weight gain.
It can also result in digestive problems over the long-term, as well as hunger, fatigue and weakness.
Speaking of the OMAD diet, Abigail Roberts, a nutritionist at bulk.com also told MailOnline: ‘Unless the meal contains all the necessary nutrients and calories required by the body, it’s unlikely to be a healthy approach to eating, especially if done over a long period.
‘Research has shown that consuming only one meal a day can lead to inadequate nutrient intake, causing deficiencies that may lead to various health problems such as fatigue, weakened immunity, and impaired cognitive function.’
The PM, who has gone from fledgling MP to Prime Minister in seven years, has even publicly confessed to dieting.
‘I do intermittent fasting,’ he stated last year, in a podcast. ‘So, on most days, I have nothing for breakfast.’
So, could intermittent fasting — whether extreme with one meal a day or the traditional version of eating within an eight-hour window — be behind Mr Sunak’s rapid rise to power?
Admirers will of course attribute this rise to the 42-year-old’s diligence, plus the academic prowess that earned him a First at Oxford University, but advocates of fasting insist it also has clear benefits.
Supporters of OMAD say it can boost productivity, improve memory and cognition, all key skills for anyone wanting to climb the career ladder.
One man, Walter Guevara, even claimed the diet brings him a ‘heightened sense of focus and clarity’.
He added: ‘I don’t check my phone every couple of minutes or find myself having 100 tabs open on my browser.’
Others have claimed it gives them ‘mental clarity’, ‘consistent levels of energy and focus’ and has improved their ‘cognitive abilities’.
Another woman, Amanda Piotrowski, told Women’s Health the diet has made her ‘clear-headed’ and ‘energetic’.
But there’s no science to prove any of these effects, experts suggest.
While it is a popular dieting trend, having shot to prominence in the early 2010s, experts have long been divided about the merits of intermittent fasting.
OMAD was made famous by model-turned-actress Liz Hurley in the early 2000s, who was admired for her age-defying figure which inspired envy in women in their 20s.
The now 57-year-old admitted to limiting herself to just one meal per day after giving birth to her son Damian in 2002, confessing that she was ‘going to bed hungry’.
But since then, OMAD has picked up mass appeal among men, most notably among Chris Martin, who became jealous of 73-year-old Bruce Springsteen’s amazing physique.
Revealing his dietary habit during an appearance on Conan O’Brien’s Needs A Friend podcast, the 46-year-old said: ‘I actually don’t have dinner any more. I stop eating at 4[pm] and I learned that from having lunch with Bruce Springsteen.’
In an interview with the Evening Standard yesterday, Gary Lineker, 62, also disclosed he ‘only really eats one major meal a day’.
The Match of The Day host said: ‘Breakfast I don’t eat, and then I’ll either pick in the evening if I’ve had lunch, or pick in the daytime, with nuts and fruits.’
Many proponents of OMAD insist it helps them manage their weight easier and keep fit.
Other intermittent diets, such as the 16:8 eating plan, are based on entirely the same principal. But followers instead fast for 16 hours a day, and eat whatever they want in the remaining eight hours — typically between 10am and 6pm.
This can be more tolerable than the infamous 5:2 diet, where calories are restricted to just 500 a day twice a week.
By creating a calorific deficit during fast days, the body instead relies on breaking down stored body fats to to create energy, aiding quicker weight loss.
OMAD was made famous by model-turned-actress Liz Hurley in the early 2000s. The now 57-year-old admitted to limiting herself to just one meal per day after giving birth to her son Damian in 2002, confessing that she was ‘going to bed hungry’. Pictured in London in January
The Prime Minister’s mother-in-law, Sudha Murty, 72, revealed her family have long observed a fast every Thursday. Pictured above, Mr Sunak with his wife Akshata Murty in Belfast on April 19, to mark the 25th anniversary of the Good Friday Agreement
But experts warned MailOnline that only consuming one meal per day could instead trigger separate health issues and toxic diet patterns, including overindulging in the hours people can eat.
Sports nutritionist Abigail Roberts said: ‘Unless the meal contains all the necessary nutrients and calories required by the body, it’s unlikely to be a healthy approach to eating, especially if done over a long period.
‘Research has shown that consuming only one meal a day can lead to inadequate nutrient intake, causing deficiencies that may lead to various health problems such as fatigue, weakened immunity, and impaired cognitive function.
‘Additionally, eating one meal per day may increase the risk of binge eating during that meal, causing digestive discomfort such as bloating and constipation.’
Intermittent fasting does have benefits ‘for some people’, Miss Roberts accepted.
But she urged anyone looking to drastically cut weight — a theme at this time of the year when many are trying to get in shape for summer — to inform their doctor.
Dietician and spokesman for the British Dietetic Association, Dr Linia Patel, also told MailOnline: ‘Whatever weight loss or health benefits you see on the OMAD diet will likely be short-lived.
‘Not eating for 23 hours will likely lead to a lack of energy, fatigue, uncontrollable cravings, and disruptions to your bowel habits.’
She added: ‘This diet is not one I would recommend as it is too restrictive, can lead to fad dieting and disordered eating.
‘There is some positive research surrounding fasting in general, showing that fasting when done in the right context could aid in weight loss and assist in preventing chronic disease,
‘If you do want to try intermittent fasting, at least go with the 16:8 method, which has you fasting for 16 hours and eating for eight. It’s not for everyone, but it’s a much more balanced approach. Speak to a dietitian for more tailored support.’
Professor Naveed Sattar, a professor of metabolic medicine at the University of Glasgow, said: ‘Any mechanism that helps people control their calorie intake will help them lose weight — the key issue is whether one meal per day is sustainable in long term.’
He told MailOnline: ‘It may not be for the vast majority of people. Rather small sustained changes in usual caloric intake with three meals per day maybe a better achievable goal for many.’
Research into OMAD specifically is still emerging.
One 2022 study, however, found participants who only ate one meal per day saw a greater reduction in their body weight and fat mass.
There was no difference in lean mass or bone density by the end of the 11-day trial, however, according to results of the 11-person project in the journal Frontiers in Physiology.
A second study a year earlier in the Journal of Animal Science and Biotechnology compared the effects of eating one large meal a day against two or six in mice.
Rodents on just one meal gained more weight than those who consumed multiple meals.
Writing for The Conversation, Dr Amanda Avery, an associate professor in nutrition and dietetics, at the University of Nottingham said: ‘There’s still a lot we don’t know about it.’
She added: ‘It’s also important to note that while this diet might work for celebrities, they also have access to nutritionists, high-quality diets and supplements where needed.
‘For most of us, this kind of diet could be unsustainable – and potentially harmful in the long run.’