This diet—popularised by a 2012 book by Michael Mosley and Mimi Spencer—is back in the news because recent research shows a program like the 5:2 can add years to your life. Also known as the Fast Diet, it allows you to eat normally for five days a week as long as you fast for two days—ideally two non-consecutive days. On fast days, you can eat no more than 500 calories if you’re a woman, 600 if you’re a man. Other days, you can eat your usual portions and even dessert, just don’t binge. That’s it, that’s the whole diet.
The promise: You’ll lose weight, of course, but studies claim this diet can also improve overall health by preventing diabetes, and lowering blood pressure and cholesterol. And according to new research, 5:2 could help you live longer too.
The science: Not only does fasting shrink your stomach’s capacity, it triggers the production of free radicals, the evil little buggers responsible for aging. Intermittent fasting produces an amount small enough that your body can figure out how to fight it and thus fight aging. Scientists at University of Florida found this out by testing subjects at the end of three weeks during which time they’d fast every alternate day. It’s like the diet equivalent of interval training.
What 500 calories looks like: Prepare to eat a lot of salad and protein. There are now special recipes catering to the 5:2 diet and it’s pretty amazing what they can fit into the calorie limit, including pancakes, stroganoff and prawn curry. If you can forget carbs exist for two days a week, you can do this.
What’s iffy: To get the longevity benefit, you have to give your body a chance to fight the free radicals. This means, the researchers say, you have to cut back on foods rich in antioxidants, like dark leafy vegetables, nuts, whole grains and beans. That’s a lot of food to cut out. Plus, diabetics might find it hard to keep sugar levels stable on 500 calories a day. Here’s a sensible list of dos and don’ts. As a program that lets you eat what you like most of the time, the 5:2 is as tempting as any miracle diet. The question is, can you live like this?
Photograph: Foodandwine.com
