“The Fast Diet” is a bestselling book that outlines a weight-loss plan in which participants can eat what they want for five days, but must fast for two non-consecutive days.
Dr. Michael Mosley, the book’s author, defines fasting as 500 calories a day for women and 600 for men. Adults can consume these calories, which amount to 25 percent of a normal adult’s daily food intake, in one mid-day meal or spread across the course of the day. But protein and lots of fruits and vegetables are highly recommended.
You’ll lose weight – specifically fat – and reduce your risk of a host of chronic diseases.
You eat normally 5 days a week, and fast for the other 2 days. Your fasting days should not be back-to-back; you should have at least 1 normal eating day in between them.
During your fast days, you can eat, but not very much. Women get 500 calories per day; men get 600. That’s far less than what’s usually recommended. Depending on age, gender, and how active you are, you could need three or four times as many calories.
The Fast Diet encourages you to eat lean protein, vegetables, and fruit on fasting days, usually as two small meals plus a few snacks.
A typical 500-calorie fasting day might include oatmeal with fresh blueberries for breakfast, a tangerine for a snack, and a chicken and vegetable stir-fry for dinner. You will drink lots of water and may also have calorie-free beverages such as tea, coffee (no milk or sugar), and club soda.
On your 5 “off days,” you can eat anything. Surprisingly, the research team that studied the diet found that people didn’t gorge themselves on off days.
The Fast Diet strongly discourages drinking alcohol on fasting days and suggests that if you drink on your “off days,” you drink only in moderation. And once you reach your weight loss goal, 1 day of fasting per week is recommended for maintenance.
The ‘Fast Diet’: Recipes
Add a delicate swirl of pomegranate molasses, along with pomegranate seeds and a dusting of cinnamon, to arrive at a wonderful, ruby-studded dish with a flash of inspiration from the Middle East. Use old-fashioned oatmeal as it will keep you fuller longer than the more processed varieties.
1 1/4 cups skimmed milk
1 ounce old-fashioned oatmeal
1/2 teaspoon ground cinnamon
A pinch of salt
1 teaspoon pomegranate molasses
Scant 2 ounces fruit of choice (stick to the lower-GI fruits such as berries and cherries)
Heat the milk, oats, cinnamon, and salt in a small saucepan. Stir well untill the oatmeal is thickened, 4 to 5 minutes (you can do this in a microwave, stirring halfway through the 5-minute cooking time). Leave to stand for a minute before adding the molasses and fruit.
Total Calories: 284
How much does Fast Diet cost?
Cost isn’t really a factor for this diet, given that you’re eating normally most days. There’s a good chance you’ll wind up buying fewer foods on fast days, and thus spend less on your grocery bills. But keep in mind that if you follow the diet authors’ advice and get your calories from high quality foods, they can be a bit pricier than cheap, high-calorie fast food cheeseburgers.
Fast Diet: Will you lose weight?
Probably. You’ll consume significantly fewer calories than you normally would on two days of the week, so there’s a good chance that if you actually stick with the plan, you’ll steadily drop weight. And because the two fast days are nonconsecutive and allow for at least some eating, the diet authors have found that people don’t typically binge and overeat on the non-fasting days.
- In a 2011 study published by the American Association for Cancer Research, researchers at Genesis Prevention Center at University Hospital in South Manchester, England tested the effects of three kinds of diets on 115 women. One diet looked like the Fast Diet (five days of normal eating and two days following a calorie-restricted, low-carb diet each week), another restricted carbs two days a week but had no calorie restrictions and a final group followed a calorie-restricted Mediterranean diet for all seven days of the week. After four months, participants following the intermittent low-carbohydate diets lost an average of 9 pounds, while those on the Mediterranean diet lost an average of 5 pounds.
- In a randomized trial of 107 overweight or obese premenopausal women, researchers found that participants who followed an intermittent food energy restriction plan (25 percent restriction two days a week) lost a comparable amount of weight to the participants who followed a continuous energy restriction plan. After six months, participants following the intermittent calorie restriction plan lost an average of 14 pounds each. Results were published in 2011 in the International Journal of Obesity.
- A study published in the July 2013 issue of Physiology & Behavior doesn’t discuss intermittent-day fasting, but it addresses the concern of overeating after fasting. Researchers at Cornell University either fed breakfast to or withheld breakfast from a group of student volunteers. They found that those who skipped breakfast reported being hungrier than those who ate breakfast. They also ate more at lunch. Still, the amount they ate didn’t fully compensate for the missed meal. Volunteers who skipped breakfast consumed 408 fewer calories over the course of the day than those who ate breakfast.
- Studies on every-other-day fasting show mixed results. One published in 2010 in the Nutrition Journal suggested that the technique was effective among a group of obese patients. A group of 16 participants ate only one meal — lunch — every other day, and they were limited to about 500 calories. That’s the same amount of calories women consume on the Fast Diet’s fasting days. On the days when the study participants were not fasting, they were not constrained to any rules. Over the course of eight weeks, the participants lost an average of 12.3 pounds.