If you just can’t give up pizza completely, maybe this diet’s for you! The FastDiet, also called the 5:2 diet, claims to help you lose weight quickly ,and it’s all based on the idea of intermittent fasting.
The diet involves eating whatever you want five days a week and “fasting” for two nonconsecutive days. On those fasting days you can eat only a fraction of your normal calorie intake — about 500 calories for women and 600 calories for men daily.
The slim-down plan is based on the No. 1 New York Times bestseller The FastDiet by Michael Mosley and Mimi Spencer. Both authors say in the book that they have used their own method and lost 20 and 15 pounds, respectively. The book claims that when you fast correctly — the authors recommend for no longer than 36 hours at a time — your body will eventually tap into fat stores for energy, but if you starve yourself for too long your metabolism will slow down significantly.
“The FastDiet demands that we think about not just what we eat, but when we eat it,” according to the book. The authors also claim the idea is backed by an evolutionary "feast and famine" perspective: that our bodies are engineered to fast because during hunter-gatherer days, people often went hungry for days at a time.
Some celebs have given the diet a try: Benedict Cumberbatch told British newspaper The Times he’s used it to slim down for roles, and Jimmy Kimmel told Men’s Journal in December he’s been on the 5:2 diet for years. “On Monday and Thursday, I eat fewer than 500 calories a day, then I eat like a pig for the other five days,” the late-night host said. "You ‘surprise' the body, keep it guessing.”
While the 5:2 may help you shed pounds, there may also be health benefits. The authors found that the FastDiet can reduce the risk of diabetes, heart disease and even some cancers. The diet book also cites an article from scientific journal Cell Metabolism that says fasting reduces many of the things that promote aging and increases the body’s ability to protect and repair itself by bolstering cellular protection.
As the possible benefits of fasting become more well known, alternate versions of the diet are also gaining popularity. Another less-extreme version of the fasting diet is the Wolverine Diet, popularized by Hugh Jackman and used by celebs including Viola Davis. This method follows a 16:8 dietary routine, where people eat all their calories for the day in an eight-hour time period and then fast for 16 hours.
Although several studies, conducted by organizations such as University of Illinois at Chicago, have backed up the weight-loss benefits of fasting, it’s still not certain that it works better than regular diets that limit daily fat and calorie intake. According to a 2010 study of young obese women by the International Journal of Obesity, those who tried intermittent fasting and those who used regular dieting methods lost a comparable amount of weight during the trial.
There can be unwanted negative effects from fasting as well. A study published by the American Journal of Clinical Nutrition concluded that intermittent fasting significantly increases hunger levels, blood pressure and cholesterol in women of average weight. Registered dietitian and nutritionist Cynthia Sass wrote a column for Health magazine that explains how fasting has seriously backfired for some of her clients. Some of the potential adverse effects are rebound overeating on non-fasting days, poor sleep quality, fewer nutrients and loss of muscle instead of fat.
If you’re interested in the FastDiet here’s how to get started: Before making any diet changes, always consult your doctor. Then, choose the two days you’re going to fast and eat foods high in protein and fiber such as fish, meat, vegetables, almonds and apples. For more info and the full plan, visit the FastDiet website.
