The "fast diet" involves eating regularly five days per week and fasting the remaining two. Adherents are supposed to consume only a quarter of their typical caloric intake, about 500 calories, for two consecutive days.
While this diet fad it taking England by storm, the concept of intermittent fasting is not new. Dr. Michael Mosley, the UK-based doctor responsible for popularizing the weight loss regimen and author of "The Fast Diet," spent months researching findings on the practice after he was diagnosed as pre-diabetic, reported the Huffington Post. Mosley opted not to take medication to manage his cholesterol and instead to make a drastic lifestyle change.
Mosley tested the diet on himself, closely monitoring his progress, and saw quick improvements. His cholesterol and insulin resistance lowered and he shed 19 pounds of fat.
"I went into it quite skeptical because I’ve looked at diets over the years and I’ve always assumed they’re rubbish. Really seriously rubbish," Mosley told the Huffington Post. "But the people who study in this area are really top scientists—world-class scientists who are hugely reputable in their areas. And they were all coming at it from their areas of expertise: cancer, dementia, diabetes—they were approaching it from different angles, but coming to the same conclusion. I found that very convincing."
All fasting is not the same, Mosley clarifies, firmly debunking the theory that juice cleansing—a recent diet rage—is beneficial.
"I think juicing is a terrible idea," he told the Huffington Post. "The biggest problem is that it removes the fiber. And the really good thing that’s in fruits and vegetables is the fiber. Fiber reduces your risk of bowel cancers — all sorts of cancers — and it also keeps you satiated and it also stabilizes your glucose levels.
If you take an apple and you eat it, you get loads of fiber in it, it fills you up. Studies show that having an apple before your meal means you’ll probably eat fewer calories in that meal. If you drink apple juice, basically, almost all the skin has been removed and all the vitamins are in the skin. A glass of juice is really just a sugar hit. And that is going to make you feel hungry, it's going to make your insulin levels go up. It’s going to be empty calories."