All About: The 5:2 Diet

5:2 Diet name on cutting board with knife, rosemary, thyme, and arugula

What is the 5:2 Diet (aka the Fast Diet)? Does it work? Is it healthy or unhealthy? Learn all of the above and more.

What is the 5:2 Diet?

The 5:2 Diet is a popular diet form that follows the fasting method. It promotes weight loss along with the health benefits of fasting. Compared to other diets, it does not involve prolonged days of calorie restriction but instead uses a 5:2 eating pattern. This ratio represents the rule of eating regularly for 5 days and reducing food intake for 2 days.

The 5:2 Diet is also known as the Fast Diet. This should not be mistaken as a quick weight loss program as ‘fast’ here does not mean quick. Refraining from eating or fasting used to be known as a religious practice but science has proven some of its medical benefits. This brought a surge of diet fads that use fasting to alter eating habits and advocate a healthier lifestyle. The 5:2 Diet is among those that use intermittent fasting; a style of diet that alternates between eating and fasting.

How does it work?

The 5:2 Diet is among the easiest diet programs to follow. A dieter is allowed to eat normally with no food restrictions for 5 days. After that, the dieter then has to abstain for 2 non-consecutive days. It is important to note that most 5:2 Diet guides suggest fasting should not be done for 2 consecutive days to avoid health risks.

The rule of the diet during the 2 days of fasting is also relatively easy. Dieters are simply advised to restrict food consumption to about a quarter of the average required daily calorie intake. An estimated overview for this would be around 500 calories for women and around 600 for men. There are also no food restrictions even during the fast days as long as the total calorie intake does not exceed 25%.

Does the 5:2 Diet work? What are the benefits of it?

Purportedly, fasting has shown positive results in the prevention and aid against illnesses like cancer, diabetes, and cardiovascular diseases. It is also claimed to help counter age-related diseases like dementia or Alzheimer’s. Reducing food intake or cutting down the calories for a particular time is also a definite way to achieve weight loss. These are also the supposed 5:2 Diet health benefits.

As the hype proposes, the 5:2 Diet results in a healthier lifestyle with a sustainable eating plan. Claims from dieters who have tried it report significant improvements in their cholesterol levels, blood pressure, and weight. The diet is not too strict so for those looking to it as a weight loss diet option, they can only expect to lose a 1-3 pounds in a week. Still, it's likely an easier and less risky option compared to other extreme low-calorie diets.

On the other hand, there are still limited reports or evidence of the efficiency of the 5:2 Diet or the Fast Diet. Some professionals conclude that the 5:2 Diet has rather similar results to healthy eating or the traditional method of dieting: sticking to the recommended number of daily calorie intake and choosing healthy food over junk food.

Is the 5:2 Diet safe? Is the 5:2 Diet unhealthy?

The 5:2 Diet does not have intense restriction nor promotes prolonged days of reduced food intake. As such, it is a comparably safe diet compared to more extreme diets. However, there is always some risk with any lifestyle change so always consult with a medical professional.

Some versions of the Fast Diet claim faster weight loss results when fasting for two days. This is not recommended especially for casual dieters who are not guided by dietitians or medical practitioners. Fasting for 2 days straight can result in energy loss and nutrient deficiency. This can also cause bad breath, headache, and may leave a dieter feeling very weak and irritable. To avoid health risks, many 5:2 Diet guides would recommend fasting for 2 separate days.

Also, people who want to try the 5:2 Diet are warned against overeating. There is a tendency for those who try the Fast Diet to eat more or eat too much during non-fast days to compensate for their 2 days of limited food intake. This does not only render the effects of a 5:2 Diet null but would also create bad eating habits.

Considering these factors, the 5:2 Diet may help dieters safely achieve their weight loss goals and alter their eating habits, although some reports suggest that its results are not much different from slightly cutting down calorie intake for 7 days. Finally, those who are pregnant, have a history of eating disorder and health issues, and those who are on medication are not advised to follow the Fast Diet without a professional’s advice.

5:2 Diet shopping list, meal plan, and menu

What makes the Fast Diet popular is because it has no food restrictions. There are, however, some 5:2 Diet ideas on what foods to eat on fast days. Food types with low amounts of calories but can help you feel fuller longer top the list. Choosing foods with high fiber and high protein count is also highly encouraged.

Here is a quick list of some food suggestions for your 5:2 Diet shopping list:

  • Vegetables: Cucumber, spinach, broccoli
  • Fruits: Blueberry, tangerine, pears
  • Protein: Lean meat, eggs, oily fish like salmon and tuna
  • Nuts: Almond, pistachios, and cashew
  • Grains: Oats, quinoa
  • Dairy: Low-fat yogurt like Greek yogurt, cottage cheese
  • Drinks: Herb teas, black coffee

For those who would like to try this fasting fad, here is a menu of 5:2 Diet meals for a fast day:


Option 1: Oatmeal with blueberries

Option 2: Low-fat Greek yogurt with sprinklings of nuts or seeds

Option 3: Boiled egg and asparagus


Option 1: Turkey breasts with spinach

Option 2: Potato and leek soup with strips of chicken

Option 3: Spiced carrot and lentil soup


Option 1: Slice of cantaloupe

Option 2: A handful of almonds

Option 3: Celery with cheese


Option 1: Baked cod

Option 2: Sirloin steak with salad

Option 3: Chicken and vegetable stir-fry

A dieter may choose to opt out of lunch or snack if the calorie count goes over the designated 25% limit for a fast day. However, as long as it stays within the restriction, a person is allowed to eat whatever recipe he or she chooses.

5:2 Diet Books

5:2 Diet Recipes

5:2 Diet Apps

Looking for more diet ideas?

Try our free Diet Optimizer Quiz and get quick, unique, customized ideas like:

  • Healthier options than soda that taste better than water.
  • Alternatives to french fries, potato chips, or other fried foods.
  • How to get your chocolate fix without the junk ingredients in candy bars.
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