Here comes a very simple trivia question: How many days are there in a week? 

Seven. That is correct! Now, how will you feel when I tell you that there exists a diet plan that claims to ‘definitely’ make you lose some pounds. Within these seven days (…if continued for many months) if you opted to fast for two days and ate whatever you wanted to for the rest of the five days of the week? 

Sounds scary and confusing at the same time? Well, don’t worry! This is an introduction to the 5:2 Diet plan. That you can follow to gain some weight loss and accelerated metabolism benefits from it. So, let us learn about what this diet plan is all about. 

What Is A 5:2 Diet Plan? 

5:2 diet

You would have already gained an idea regarding the basics of this 5:2 Diet from above. It is also known as the ‘Fast Diet.’ [1]

Remember that the term ‘fast’ here does not refer to the speedy ‘fast,’ but rather the fasting. Or the abstinence from food. This diet plan allows you to fast for two days a week. And remain fast-free for the rest of the week. 

However, we need to dive deep into its history to learn more about how it came into being. And how it will help all the weight-conscious people in putting some pounds off. 

Background Of The 5:2 Diet

5:2 diet

The 5:2 Diet Plan was introduced to the world by a journalist and doctor, Micheal Mosley. He referred to this diet as a ‘revolutionary’ diet. Claiming that it had far more benefits than any other diet plan that exists in the world today. 

A month after he had released his book titled ‘The Fast Diet,’ another BBC journalist, Kate Harrison, published another book called ‘The 5:2 Diet Book’. This book is what we can call a proper introduction to this particular diet plan to the book. Although the basic foundation of both the books was based on the same rules of fasting. [2]

How Does The 5:2 Diet Plan Work?

The 5:2 Diet Plan or the ‘Fast Diet’ is based on the basic principles of ‘Intermittent Fasting.’ In this type of fasting – or rather, in this particular lifestyle. A person is supposed to fast or avoid eating anything significant for a specified amount of time during the day. [3]

Then after this period is over, you become free to eat or drink anything that you want to have. As long as it is within your ‘allowed’ daily limit of calories. 

The idea is to make the body enter into a fasting state. Thus, when the body senses that it is not getting the food that it was used to getting during particular times of the day. It will ultimately go into ‘survival’ mode and start using its stored fat storage to release glucose and make sure that you do not run out of energy during any time of the day. [4]

If you still continue fasting, the body will have to resort to breaking down other of its fat storage, and this way, some or all of the excess fat stored in your body will get broken down and, ultimately, would help in weight loss in the longer term. 

Overall, it is the idea of ‘calorie deficit’ that will help you get rid of your body’s excess fat storage to aid in weight loss. [5]

The 5:2 Diet Calories: How Many Are Allowed Per Day? 

5:2 diet

Since the 5:2 Diet Plan strictly revolves around sticking to the fasting plan for two days of the week, it is common sense to know that during these two days, you will be reducing your calorie intake to more than half of what you usually consume in a day. 

It is usually recommended that men follow this diet plan and consume 600 calories per day, whereas women should ideally consume up to 500 calories per day. [6]

The breakdown of these calories is totally up to the person following the diet – you can choose to break down the diet into portions that feel suitable to you. It will be you against the diet, so it is better to consume more calories during that part of the day when you know that you are going to be the most productive and simultaneously leave the least number of calories for the time when you know that you will not be working or be too much activity during the day. 

5:2 Diet Benefits – The Convincing Side Of The Picture! 

Just like everything else connected to your health and body, this particular diet has more to do with you than just helping you lose some weight. It turns out that there are several health benefits of incorporating the 5:2 Diet into your daily life. [7]

Only reading about them will make you want to pursue this particular diet for a short time, if not for long enough! 

So, let us read more about what the 5:2 Diet has in store for us! 

No Restricted Food Items! 

This benefit mainly refers to all the food-lovers and people who just cannot seem to give up on their beloved food items. For such people, this is good news. 

Thankfully, unlike the other popular diet plans, you will not be asked to give up on ANY favorite food item! Yes, this is indeed true! 

The 5:2 Diet Plan preaches a simple approach – to eat in moderation. So, as long as you eat your favorite food within the specified calorie count, you are safe and good to go ahead! 

Improved Blood Glucose Levels: 

For people suffering from uncontrolled blood glucose levels or those recently given a scare that they may be at risk of developing diabetes (that is, prediabetics!), the 5:2 Diet may be the perfect life-saving plan for you. 

It has been found that these fasting diets can help stabilize the blood glucose levels so that there are no unexpected spikes in them, and you can maintain a healthy schedule without them coming to disturb you whenever and wherever! 

Moreover, the 5:2 Diet also helps in reducing insulin resistance, which, once again, maintains the blood glucose levels within their optimal ranges. [8]

Promotes A Sustainable Metabolism:  

Unlike other diet plans requiring you to follow the same, or even a ‘boring’ routine every day, the 5:2 Diet Plan comes with some relaxation.

With this diet plan, you will only be strictly practicing the diet routine for two days of the week. For the rest of the week, you can relax – but only within the specific caloric ‘limits’ made clear to you. [9]

In this way, not only you but your body will also relax. It will soon adapt to this new but unique pattern where it will get all the food that it needs for some days of the week but will have to avoid it for some other days. This is a healthy practice and will make your body healthy and active in the longer run. 

The 5:2 Diet Side Effects – What You Should Stay Mindful About! 

5:2 diet

There are obvious advantages and disadvantages for everything, but some drawbacks exist with the 5:2 Diet Plan. 

For starters, the fasting routine may be tiring and draining for many people. Such people are bound to experience hunger pangs or bouts of overeating once they resume eating, and so, following the 5:2 Diet may turn out to be a nuisance for them. 

Brain fog is yet another ‘side effect’ that may accompany fasting, though it usually resolves over the day and is nothing to worry about in most cases. 

Apart from this, people who are underweight, malnourished, or suffering from chronic illnesses such as Diabetes, Thyroid Disorders, or even pregnant or breastfeeding women should avoid this diet. The reason for this is that this dieting pattern may alter the hormone levels and lead to problems, which is something that nobody wants for sure! [10]

Conclusion – Is The 5:2 Diet Plan Suitable For Me? 

With so many conflicts and benefits laid down in front of you, it is obvious that you may feel confused about what option to go ahead with. 

Well, the 5:2 Diet is a healthy option for people looking to opt for an active and healthier lifestyle. It has simple principles and will never force you to follow strict or tough schedules or patterns to get into motion. 

However, you can always choose to skip this diet plan if you feel it will not suit your lifestyle or make you go crazy-hungry. There are always better options available out there, so maybe this might just won’t be the right one for you. 

You can easily make up your 5:2 Diet meal plans at your convenience. Some people opt for fasting for two consecutive days, whereas some prefer doing it on alternative days. 

In both cases, you will be experiencing the benefits of this diet plan within a few weeks, and that would be the best part indeed. So, are you ready to jump into the 5:2 Diet Plan and get some action going already? 

Disclaimer: This article is only a guide. It does not substitute the advice given by your own healthcare professional. Before making any health-related decision, consult your healthcare professional.

Editorial References And Fact-Checking

  • Scholtens, E. L., Krebs, J. D., Corley, B. T., & Hall, R. M. (2020). Intermittent fasting 5:2 diet: What is the macronutrient and micronutrient intake and composition?. Clinical nutrition (Edinburgh, Scotland)39(11), 3354–3360.
  • Hajek, P., Przulj, D., Pesola, F., McRobbie, H., Peerbux, S., Phillips-Waller, A., Bisal, N., & Myers Smith, K. (2021). A randomised controlled trial of the 5:2 diet. PloS one16(11), e0258853.
  • Conley, M., Le Fevre, L., Haywood, C., & Proietto, J. (2018). Is two days of intermittent energy restriction per week a feasible weight loss approach in obese males? A randomised pilot study. Nutrition & dietetics: the journal of the Dietitians Association of Australia75(1), 65–72.
  • Templeman, I., Gonzalez, J. T., Thompson, D., & Betts, J. A. (2020). The role of intermittent fasting and meal timing in weight management and metabolic health. The Proceedings of the Nutrition Society79(1), 76–87.
  • Strasser, B., Spreitzer, A., & Haber, P. (2007). Fat loss depends on energy deficit only, independently of the method for weight loss. Annals of nutrition & metabolism51(5), 428–432.
  • Gao, Y., Tsintzas, K., Macdonald, I. A., Cordon, S. M., & Taylor, M. A. (2022). Effects of intermittent (5:2) or continuous energy restriction on basal and postprandial metabolism: a randomised study in normal-weight, young participants. European journal of clinical nutrition76(1), 65–73.
  • Collier R. (2013). Intermittent fasting: the science of going without. CMAJ : Canadian Medical Association journal = journal de l’Association medicale canadienne185(9), E363–E364.
  • Albosta, M., & Bakke, J. (2021). Intermittent fasting: is there a role in the treatment of diabetes? A review of the literature and guide for primary care physicians. Clinical diabetes and endocrinology7(1), 3.
  • Patterson, R. E., & Sears, D. D. (2017). Metabolic Effects of Intermittent Fasting. Annual review of nutrition37, 371–393.
  • Wilhelmi de Toledo, F., Grundler, F., Sirtori, C. R., & Ruscica, M. (2020). Unravelling the health effects of fasting: a long road from obesity treatment to healthy life span increase and improved cognition. Annals of medicine52(5), 147–161.


  • Dr Andleeb Asghar, Pharm.D

    Dr Andleeb is a Doctor of Pharmacy (Pharm.D) graduate with real-life experience working in health and wellness-related companies. She has also published various research papers in the health and medical field. Currently, she takes joy in creating health-related content for a wide range of audiences, which is a craft she has been perfecting for over five years. She enjoys diving deep into published research papers and journal articles to source helpful content for her readers. LinkedIn


Dr Andleeb is a Doctor of Pharmacy (Pharm.D) graduate with real-life experience working in health and wellness-related companies. She has also published various research papers in the health and medical field. Currently, she takes joy in creating health-related content for a wide range of audiences, which is a craft she has been perfecting for over five years. She enjoys diving deep into published research papers and journal articles to source helpful content for her readers. LinkedIn