I saw some articles on a new book, “ The Fast Diet ,” that has been popular in the UK. Now it has been released in the US, and it is already the #1 best seller at Amazon.
I predict this diet will be trendy in 2013. But unlike your typical fad diets, I think this book is actually a move in the right direction.
The core of the diet is to restrict calories on two non-consecutive days per week (down to 500 or 600 calories). On the other days, a person eats normally with no real restrictions. This is essentially intermittent calorie restriction, which I’ve written about before, as early as 2008 .
All signs point towards intermittent calorie restriction being better than chronic calorie restriction. If you restrict calories every day, then the body adjusts and the metabolism slows. With intermittent calorie restriction, this doesn’t appear to be the case.
The key thing in my opinion is that on these days of low calorie intake there should be exercise. A couple of recent studies support this. Here it shows how muscle physiology changes for the better when you exercise the muscle on low energy intake. This study shows how alternate day fasting combined with aerobic exercise leads to maintenance of lean mass with weight loss.
I don’t have the Fast Diet book, so I’m not sure if it emphasizes exercise on the fast days. But this is a big key to long-term success in my opinion.