Now, armed with new medical research, feedback from 5:2 dieters and some bold experimenting on himself, Mosley is back with a revised approach to intermittent fasting. His latest book, The Fast 800, lays out how to combine rapid weight loss and intermittent fasting, with achievable meal-plans and long-term health goals.
While the 5:2 diet recommended two fast days a week of around 600 calories for men and 500 calories for women – eating normally on the other five days – the Fast 800 is based on recent studies that show 800 calories is the magic number when it comes to successful dieting: “It’s an amount high enough to be manageable but low enough to speed weight loss and trigger a range of desirable metabolic changes,” says Mosley. “On 800 calories a day you can expect to lose up to 5kg after two weeks, 9kg after four weeks and 14kg after eight weeks, most of which will be fat.”
Mosley concedes that not everyone can or will want to stick to 800 calories a day for long. After a few weeks of rapid weight loss, dieters looking for a more balanced regimen can switch to a new version of the 5:2 – one that helps maintain muscle mass and stops the metabolic rate from crashing as the weight comes off.
Mosley also introduces readers to a relatively new form of intermittent fasting called time restricted eating (TRE). “TRE has taken the internet by storm, particularly among the body-conscious under-30s,” he writes. “It involves eating all your calories within a relatively narrow time window each day, usually 8 to 12 hours. This extends the length of your normal overnight fast (the time when you are asleep and not eating) and gives your body an opportunity to burn fat and do essential repairs.”
Other benefits of the long-term diet plan include lowered blood pressure, reduced risk of developing type 2 diabetes and better sleep.
You can catch Dr Michael Mosley in person, in Auckland on January 21, 2019, when he will be talking about The Fast 800 – and taking your questions on food, fasting and gut health. The NOTED Live event will be held at the Auckland University of Technology. For tickets, see here.