Why do these celebrities eat just one meal a day?

Most articles about diets tend to focus on women. This time, however, the focus is on a particularly extreme diet and the men that adhere to it.

Coldplay frontman Chris Martin, Bruce Springsteen, and even UK Prime Minister Rishi Sunak are all fighting against being middle-aged thanks to a one-meal-a-day fasting diet. 

But how safe is eating one meal per day?

Supporters of intermittent fasting say that this diet helps weight management, but experts warn it can spark health issues and unhealthy eating patterns. This is one of Hollywood's favorite diets and has legions of fans, including high-profile celebrities like Jennifer Aniston. But now there's an even more extreme version: The OMAD diet.

Short for "One Meal a Day," this diet sees people eat just one meal a day and fast for 23 hours, during which you can only drink coffee without milk, herbal tea, and other calorie-free drink.

Sunak recently revealed that he is also a follower of this diet, or at least on occasion. 

So is intermittent fasting – whether it's extreme with one meal a day or the traditional version of eating within an eight-hour window – healthy?

OMAD supporters say it can make you more productive and have improved memory and cognition. Some also say it provides a heightened sense of focus and clarity.

Go to sleep hungry

Actress Elizabeth Hurley popularized the OMAD diet in the early 2000s. At the time, she admitted that she limited herself to just a single meal each day after giving birth in 2002 and said she would go to bed hungry.

Since then, the diet has gained popularity among men, with some pointing to how Bruce Springsteen has maintained his own physique even at the age of 73.

There are a number of different intermittent fasting diets that are all based on the same principle. There's the 16:8 plan, which limits eating to an eight-hour window. Then there's the infamous 5:2 diet, which sees two days a week where you limit yourself to eating just 500 calories.

The idea behind all of them is simple. Fasting creates a caloric deficit. This causes the body on breaking down the stored fats to create energy, thus burning through calories and helping to lose weight faster.

What does the research say about the OMAD diet?

But experts warn that eating just one meal a day can trigger health problems and unhealthy eating patterns, including overindulging during the hours when people can eat.

Research on the OMAD diet is still ongoing. One 2022 study published in Frontiers in Physiology found that participants who ate just a single meal a day saw a greater decrease in body weight and fat content but without any difference in bone density.

Another study published two years earlier in the Journal of Animal Science and Biotechnology compared these eating habits in mice. That study found that mice who ate just one meal a day gained more weight than the ones who ate multiple meals.