This month, the takeaway delivery service Deliveroo announced plans to float on the London Stock Exchange in an IPO worth up to £8 billion – proof that we are not only eating more takeaways, but too lazy to pick them up ourselves.

Maybe this is just the time then to also order a copy of Intuitive Fasting: The Flexible Four-Week Intermittent Fasting Plan to Recharge Your Metabolism and Renew Your Health (Hodder) by functional medical expert Dr Will Cole.

Boasting devotees including Gwyneth Paltrow and Elle Macpherson, Dr Cole’s programme is the latest to tap into the growing popularity of fasting as a way of controlling weight, protecting against disease and helping you live longer. Such diets focus on when you eat, rather than what you eat, with regular periods of fasting thought to reset and rebalance the body – making you not only slimmer but more energetic too.

Dr Cole is causing a stir thanks to glowing endorsements from Paltrow, 48, who calls his book "doable and exhilarating" – but fasting diets like his are proving to work well for men too.

British Prime Minister Boris Johnson is one. His personal trainer, Harry Jameson is an advocate of the 16:8 diet that allows participants eight hours each day to consume their daily allowance of calories. Johnson reportedly skips breakfast or lunch as part of his new regimen – which is being combined with a vigorous fitness schedule.

Popularised by Dr Michael Mosley in his book The Fast Diet, the 5:2 allows you to eat as normal for five days of the week but fast on the other two, limiting your calorie intake to around 800 a day. Recently, Mosley has also promoted The Fast 800, a new 12-week schedule that involves cutting your calories to a limit of 800 per day for the first two weeks before reverting to the 5:2 plan. The benefits, explains Dr Mosley, go beyond just shedding the kilos. "You should not only see rapid weight loss but big improvements in blood sugars and blood pressure, too," he says.

With no foods off limits, and the ability to adjust it around your own schedule, fasting’s appeal lies in its simplicity.

Dr Mosley says men tend to see results faster than women, especially in terms of weight loss. "As men possess more muscle, than women, they could lose weight more rapidly. Adding resistance exercise helps in maximising results."

Evidence shows that fasting diets are more effective than conventional daily calorie reduction for weight loss and improved blood sugar markers. But its macho image is also bolstered by claims that fasting has benefits for the brain and improves performance at work.

The effect is thought to be down to autophagy – a process that kicks in when your body has been without food for 12 hours or more, whereby old or damaged cells are cleared away to make way for new ones. "Fasting allows your body time to do a bit of spring cleaning and switch on those repair mechanisms," says Dr Mosley.

"You are not supposed to be eating 24 hours a day," says Jason Fung, author of The Obesity Code. "During feeding you store energy and during fasting, you burn it. If you are always feeding, you can’t burn body fat. As such, fasting should be done every day – about 10-14 hours."

Indeed, while fasting programmes such as the 5:2 or 16:8 offer structured windows of time for eating and fasting, Dr Cole’s ‘intuitive fasting’ is about eating when your body tells you to and ignoring set meal times and patterns, ensuring you build in periods of fasting. "Many of us have never asked questions like: do I eat because I’m hungry – or because my brain is telling me to?" he writes. "What and when we eat has become so ingrained in our lifestyle that we have never asked ourselves if the way we eat is working for us."

The Daily Telegraph

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