One meal a day diet: The pros and cons of extreme fasting according to a Harvard University-educated doctor

The plan helped Dr Van Tulleken successfully lose six stone

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The idea of regularly skipping meals might sound nightmarish but according to one doctor it could be the key to maintainable weight loss.

Intermittent fasting diets have skyrocketed in popularity over the past few years – from the 5:2 to the ‘two weeks on, two weeks off’ plan – but this latest concept might be the most extreme yet.

Called the ‘one meal a day diet’, the concept is simple and involves getting your daily calories, nutrients and energy from just one meal rather than the traditional three plus snacks, Get The Gloss reports.

An advocate of the eating plan, Dr Xand Van Tulleken – a Harvard and Oxford University-educated doctor - says that as well as being scientifically endorsed, this approach could prove more convenient for dieters and produce impressive weight-loss results without the need for excessive calorie counting.

In his recently published book How to Lose Weight Well, Dr Van Tulleken explains that there’s a “large amount of medical evidence that indicates fasting is a safe and effective way of losing weight.”

And, that while the way in which it works isn't quite clear, “some researchers describe fasting as being a good kind of stress on your body, like exercise, and that it promotes fat burning.”

Similarly, unlike traditional diets it means that you can eat what you like, when you like - within reason - and doesn’t rely on having to source obscure, expensive ingredients.

Followers can also have their one main meal whenever it suits them and while Van Tulleken acknowledges that while it can be tough at first, he says the plan will help you realise it’s okay to feel hungry.

“Fasting can be a shock to the system and the first day you're likely to feel hungry. It does get better.

My way of dealing with hunger is to remember that feeling hungry isn't too bad and it is possible to function quite well when you're hungry.”

When it comes to fasting, the NHS emphasise the importance of eating high-energy meals to prevent muscle wastage so as long as you’re getting a good balance of carbohydrate, protein, fat and fibre you will remain in good shape.

Of course, like most diets the ‘one meal a day’ plan does have its downsides - and Van Tulleken says it’s important to understand we do function less well when we’re hungry.

As such, he recommends only fasting on days that work for you and that depending on your job, personal health and activity levels, it might not be the right route for you.

It also raises the concern for overeating as many participants can see eating just one meal a day as a hall pass to consume whatever they like. Likewise, the British Dietetic Association commented that the plan could leave you lacking in energy or nutrients.

“A mix and match approach to the meal plans is most likely. On the one-meal a day plan, the diet is also low in several nutrients, but especially lacking in calcium, so we would advise adding some milk or yoghurt into the plan if you are going to follow this in the longer term.”

Ultimately, to fast successfully you should be eating your one meal when you are really hungry and ensuring your plate is balanced, fulfilling and tailored specifically to your needs.