The 5:2 diet (Intermittent Fasting)

5 to 2 diet in diet comparison

The 5:2 diet: What is it and how does it work?

The 5:2 diet is a version of intermittent fasting, which in turn is a spin off of classic therapeutic fasting. It is specially designed to reduce weight and to settle you down to your ideal weight through short periods of fasting. The principle behind it is as follows: the week is divided into 5 non-fasting days and 2 fasting days. On the non-fasting days you can eat as normal. Ideally of course, normal means a healthy and balanced diet. However, no calorie deficit is implemented on these days. On the two fasting days, however, a maximum of 500 kcal for women and 600 kcal for men are eaten. In order to make full use of the small amount of calories, they should ideally be consumed in two smaller meals consisting of mainly vegetables. The choice of when to fast during the week is up to the individual. However, the fasting days should always be on the same days of the week.

What is allowed in a 5:2 diet?

In all forms of intermittent fasting, including the 5:2 method, it is not clearly defined which foods are allowed and which should be avoided – you can decide. However, one should of course make sure that the diet on the non-fasting days is always healthy and balanced in order to achieve lasting success. On fasting days, the diet should consist predominantly of vegetables.

For whom is the 5:2 diet suitable?

  • This type of diet is suitable for all healthy and disciplined people.
  • Due to the 5 “normal” eating days, the 5:2 is often not perceived as a diet, as you only have to make an increased effort on 2 days a week.
  • On these two days, however, a lot of discipline is required and the permission to consume just a few calories can become a great temptation. The temptation to eat anything you like can also be great on the non fasting days since there are no official guidelines for those days.
  • It is also suitable for long term use and can be used as a permanent change of diet.

Advantages and disadvantages of the 5:2 diet

Advantages Disadvantages
You do not have to stick to a calorie deficit, so there’s no hunger, on your non-fasting days It can be difficult to consume so few calories on fasting days. Many people report severe food cravings at the beginning of the diet. It is often perceived to be easier to simply not eat anything at all. If you do not meticulously count calories, you quickly run the risk of exceeding your calorie target.
There is no tedious calorie counting on your non-fasting days. It is sensible to count calories every day. A diet during which one starves for 2 days a week and then over indulges on the other 5 days will not lead to weight reduction.
There are no restrictions on certain foods so you can draw from the full repertoire of healthy food. The periodic hunger may lead you to ‘treat yourself’ as a reward on non-fasting days. Keeping a healthy diet on the non-fasting days therefore requires discipline.
No increase in cooking time/effort, the effort actually decreases on fasting days. The sudden reduction in calories creates a mental and physical challenge, particularly at the beginning.
You can fit the fasting days around your schedule. Fixed days of the week are sensible for the diet and require good advance planning.

The 5:2 diet in detail

How individual is the 5:2 diet?

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  • In the 5:2 diet, it is not prescribed how much, or what, should be eaten on the five non-fasting days. On these days there are no limits, but if you want to achieve sustainable results, your diet should be healthy and balanced.
  • The 5:2 diet can easily be combined with other special diets.
  • No calorie amount is specified for the non-fasting days. On the one hand, this gives you freedom and scope for individuality to adapt the calorie requirement to your body, on the other hand the diet does not help you to find out exactly what you need.
  • There are no rules for when the fasting days should be, but you should keep them on the same days each week and on days on which there is at most a moderate amount of exercise.

How flexible is the 5:2 diet?

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  • Only the 2 fasting days are prescribed. You can choose which days you carry them out on so you can fit them in around your week.
  • Since the fasting days do not require increased cooking effort or planning, you can also do them on busy days.
  • By the (almost) or complete renunciation of solid food on fasting days, eating out can be a little more difficult. However, 500-600 kcal are allowed and therefore a visit to a restaurant is also possible as long as you eat a light meal and abstain for the rest of the day.

How suitable for everyday life is the 5:2 diet?

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  • The 5:2 diet can be adapted to fit perfectly around everyday life.
  • It does not require a complex change of diet and does not restrict your choice of food in any way.
  • Neither the time required to prepare meals, nor the price of your weekly shop increases with this diet and it can therefore be integrated very well into everyday life, even alongside work.
  • Testimonials show that many people find reducing the amount of calories on their fasting days to such a small number more difficult than doing without food completely. Reports of unbearable food cravings and hunger are not uncommon.
  • It is advisable to carry out your fasting days on the same days each week. To achieve results on this diet it is important to eat healthily on the non-fasting days too with lots of vegetables, lean protein sources and little sugar.
  • Es ist ratsam die Fastentage regelmäßig an den gleichen Wochentagen durchzuführen, zum zweiten sollte die Ernährung an den normalen Tagen auch in eine gesunde Richtung mit viel Gemüse, mageren Eiweißquellen und wenig Zucker angepasst werden.

How scientific is the 5:2 diet?

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  • The 5:2 diet is a flexible variant of intermittent fasting, which allows for weight loss and can still be accompanied by intensive sport.
  • The 5:2 diet is a diet that focuses on calorie restriction through two fasting days. Fewer calories should be consumed over the week as a whole in order to lose weight.
  • It is advisable to carry out the fasting days on the same days each week. To achieve results on this diet it is important to eat healthily on the non-fasting days too with lots of vegetables, lean protein sources and little sugar.
  • Testimonials show that many people find reducing the amount of calories on their fasting days to such a small number more difficult than doing without food completely. Reports of unbearable food cravings and hunger are not uncommon.
  • Changing from a phase of normal eating to a phase with a very low calorie intake on two days of the week leads to a moderate reduction in total calories over the week.
  • The change from a phase of normal food supply and a corresponding build-up of body cells to a phase of limited food supply, as was commonplace for our early ancestors, has some reported health benefits for us, especially when it comes to reducing excess weight and preventing diseases. In this context, the fasting days are intended to stimulate the regeneration of the body’s own cells.
  • Studies on animals suggest that a permanent, slight reduction in calories makes us more resistant to diseases and reduces mortality.

How sustainable is the 5:2 diet and what risks does it entail?

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  • Sustainability is one of the big advantages of the 5:2 diet. By losing weight moderately and levelling off to the ideal weight, one avoids the risk of the yoyo effect and can achieve long-term success. However, this form of nutrition requires a high level of discipline in the long term. This diet will not compensate for regular slip ups, whether on the fasting or non-fasting days.
  • Muscle mass can also be maintained with a protein-rich, healthy diet without a calorie deficit.
  • One risk posed by this form of intermittent fasting is discipline. The fact that you are allowed to consume a very small number of calories on fasting days creates temptation and challenges self-discipline very much. On non-fasting days, which are not officially bound by any rules, the risk of an excess calorie intake is also high.
  • There are no health risks for healthy people following this diet.

Summary and evaluation

This variant of intermittent fasting is suitable for everyday life and can be successfully carried out by disciplined and well-organized people. The division into 2 fasting days and 5 “normal” days is very user-friendly. It is easy to understand and can therefore be carried out permanently. The 5:2 diet helps people discover their ideal weight and maintain this weight in the long term. Although the fasting days are very difficult at the beginning, they become easier and the feeling of hunger on those days should decrease over time. Our feedback on this diet is as follows:

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Customizability ◆◆◆◆◇
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Suitability for everyday use & feasibility ◆◆◆◆◇
Scientific basis ◆◆◆◇◇
Sustainability ◆◆◆◆◇
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Intermittent fasting and Upfit: varied nutrition with your individual diet plan

Nutrition is the key to permanent weight loss success. A successful weight loss plan should suit you and take your preferences and any allergies into account. Upfit gives you the opportunity to adapt your diet plan to your individual needs and will help you lose weight in a healthy way.

In just a few steps you can create a personalised meal plan based on your desired weight, the time you have available for cooking and your level of activity. Then watch the pounds drop off.

If you don’t want to do an extreme version of therapeutic fasting, then this modified method of intermittent fasting might be right for you.

If you would like to learn more about intermittent fasting, then take a look at our detailed discussion of intermittent fasting.


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