Starting with 5 Day Fast
What the programme is, what you get and how you prepare.
5 Day Fast is a structured 5-day fasting mimicking programme.
You don't stop eating completely. Instead, you get an adaptable menu with specific, high-quality vegetables, fruit and nuts, supported by supplements and guidance. Alongside nutrition, the programme also includes daily sport and exercise activities. The goal is to mimic certain effects of fasting, without stopping eating completely.
Want to understand the full programme better before you order? Check out the 5 Day Fast product page.
You get the supplements for the 5 days, access to your menu choice, a shopping list, a handy checklist with clear explanations and instructions, and an exercise plan to support you.
The aim is to prevent guesswork. You'll know what to take, what you can eat, what to buy, and how to structure the 5 days.
Choose a quiet week, plan your shopping, and avoid heavy training or stressful commitments during the 5 days.
Good preparation consists of:
choosing your menu in good time
buying your ingredients before day 1
cutting down on caffeine before you start if you normally drink a lot of coffee
planning light exercise instead of heavy training
ensuring you have enough time to sleep and recover
Don't start if you are ill, highly stressed, or injured, or if you are not sure if the program is right for you.
Yes, you can do 5 Day Fast together with your partner. You do both need your own 5 Day Fast programme, though. That's why we offer a duo discount: two programmes for €218 instead of €238.
After your order, you will receive one email with a link to put together your personal menu. If your order contains multiple programmes, you can use the same link multiple times. Are you both choosing the same menu? Then you simply double the quantities on the shopping list. Do you want different menus? Then each person fills in the form separately with their own name and email address.
5 Day Fast is designed to be repeated periodically.
The effects of a single 5-day programme last longer than the 5 days themselves, especially when you use the post-programme phase to better build up your nutrition, training and lifestyle habits. The long-term value is mainly in using 5 Day Fast as a tool to become increasingly metabolically flexible.
For most healthy adults, 2 to 4 times a year is a practical guideline to work structurally on your health, your metabolic flexibility and a healthy lifestyle in the long term.
The right frequency depends on your goal, body weight, recovery, lifestyle and how well you respond to the programme.
Don't repeat 5 Day Fast too often and don't use it to compensate for overeating. The goal is to create a structured reset at key moments and maintain the benefits between cycles with good nutrition, exercise, sleep and recovery. Do 5 Day Fast a maximum of once a month.
Ordering & delivery
Shipping, Belgium, discount codes, invoices and changes.
You'll receive the menu choice link by email within a few minutes of your order. Use this link to choose your personal menu. Don't forget to check your spam folder too.
Ordering on workdays before 18:00? Then your package gets shipped the same day. Orders on Saturday mornings before 12:00 are also processed and shipped the same day.
As soon as your package has been shipped, you'll receive a Track & Trace code. PostNL usually delivers the next working day.
If you still haven't received your order after 7 working days, please get in touch with us at support@5dayfast.nl.
Yes, we also deliver to Belgium via the webshop.
Do you want to order from another European country? Then we might be able to manually create an order for you. Extra shipping costs may apply.
Get in touch with us via support@5dayfast.nl, so we can see what's possible.
Enter your discount code in the discount code field during checkout.
Enter the code exactly as you received it. The code is automatically applied when you click the order button. If for some reason the code wasn't applied and you've already paid, please contact us at support@5dayfast.nl. We'll check this and sort it out via a refund.
Yes, you can request an invoice.
Send your order number and invoice details to support@5dayfast.nl. We will then send you the invoice.
Get in touch with us as soon as possible if you want to cancel or change your order.
If your order hasn't been sent yet, we can usually still cancel or change it. If the order has already been sent, that's usually no longer possible in the same way. Get in touch anyway, and we'll look for a solution together.
During 5 Day Fast, you follow an adaptable 5-day menu based on specific, approved foods.
The food products aren't chosen at random. Every ingredient has a function within the overall structure of the menu. The goal is to keep the right balance of calories, carbs, fats, and proteins during the 5 days, fully in line with the principles behind fasting mimicking diets research.
The menu might consist of, for example, nuts, fruit, dried fruit, olive oil, vegetables, and other plant-based ingredients. These are carefully combined and weighed, keeping your meals structured while still giving you flexibility in your choices.
You buy the ingredients yourself using the shopping list we send you. This keeps the programme flexible, while the menu tells you exactly what to eat, how much, and when.
During the 5 Day Fast, you follow a structured 5-day menu with breakfast, lunch, dinner and snacks. You can change the order around, for example having lunch as dinner or vice versa, as long as you do this within the same day.
After ordering, you'll receive your personal menu and shopping list. The menu tells you exactly what you can eat at any time of the day and how to prepare the meals. The shopping list shows you which ingredients you need to buy yourself.
The programme also contains all the supplements for the 5 days, clear instructions on when to take them, and practical suggestions for sport and exercise, tailored to your level.
Yes, you'll get a shopping list after you've chosen your personal menu.
The shopping list shows you which ingredients you'll need for the 5 days. This helps you prepare well before day 1 and avoids last-minute changes during the programme.
Yes, you prepare your own meals.
The recipes are practical and easy to make. Do plan your shopping and meal prep before you start.
The 5 Day Fast menu uses simple, plant-based ingredients that fit within the structure of the fasting mimicking programme.
The ingredients aren't chosen at random. Every single ingredient plays a part in the total macronutrient balance of the 5 days. The menu is built like a puzzle: the food products are combined and weighed so that your total intake of calories, fats, carbs, and proteins stays within the structure of the programme.
Depending on your menu choices, the ingredients consist of nuts, fruit, dried fruit, olive oil, vegetables, soups, and other plant-based products. Some breakfast options, for example, contain cashew nuts, apple, or dried apricots.
You buy the ingredients yourself using the shopping list. This tells you exactly what you need for your menu, so you don't have to calculate portions or guess which foods are allowed.
We recommend organic products where possible, as they fit the quality standard of the programme: the highest possible quality food products.
Choose certified organic products when they are available and fit your budget. Can't find everything organic? Then choose the best available alternative and stick as close to the menu as possible.
You can do your shopping at your own trusted supermarket, organic shop or local shop.
If you don't like an ingredient, can't find it, or are allergic to it, just send us an email at support@5dayfast.nl. We can suggest an alternative for almost all products to keep the structure of the programme intact.
Don't change the menu yourself, as the programme is built around specific quantities.
Yes. The amounts of food are not adjusted based on body weight. They are fixed in the programme and are the same for everyone. For everyone, it is the case that you consume less energy during the 5 days than your resting metabolic rate: the energy your body uses in a day if you were to do nothing.
How big that difference is, varies from person to person, because heavier or taller people generally have a higher resting metabolic rate than lighter or smaller people. The protocol has been researched with fixed amounts, and that is why we stick to them.
You can, however, personalise your menu by choosing from the available meal options. So, not everyone eats exactly the same meals, but the structure and amounts remain the same.
You can drink unlimited water and sparkling water during the 5 Day Fast.
Caffeine isn't allowed during the programme. That means no coffee, no energy drinks, and no caffeinated pre-workouts. Even decaf coffee isn't part of the programme.
Herbal infusions are allowed, as long as they don't contain tea leaves, green tea, black tea, or added caffeine.
During 5 Day Fast, you avoid caffeine to keep the programme clean and give your body a short break from daily stimulation.
Caffeine can make it harder to recognise your natural signs of fatigue, because it affects the adenosine system, which is involved in sleep pressure and recovery.
For people who drink a lot of coffee, this break can also be useful to reduce caffeine tolerance and become more aware of their relationship with coffee. After a few days without caffeine, some people notice that they use coffee more mindfully again, rather than automatically relying on it.
Coffee can also trigger a physical response even if there is very little caffeine in it. During the programme, the goal is to create as much physiological rest as possible and limit unnecessary stress responses.
If you normally drink a lot of coffee, you might experience headaches, fatigue or less focus in the first few days. That is a common reaction when caffeine intake suddenly drops.
Don't add extra food without checking the instructions.
The program works with a controlled intake. Extra food might change the intended structure of the 5 Day Fast.
Is hunger getting tricky? Start moving. It might sound contradictory, but it really works.
If you don't follow the programme strictly, the effect might change.
Extra food, wrong replacements, caffeine, alcohol or unplanned supplements could disrupt the intended structure of the 5 days. One small deviation doesn't mean everything is lost, but the more accurately you follow the programme, the clearer the structure remains.
Does something go wrong? Then contact support instead of trying to correct it yourself.
Supplements & ingredients
Which supplements you get and what you're allowed to use yourself.
5 Day Fast contains all the supplements needed for the 5-day programme:
Omega-3 vegan
Glycerol
Spirulina
ION Gut Support
Magnesium
Multivitamine
NAC
You'll receive the exact amounts needed for the 5 days, along with clear instructions on when to take each supplement. You can read more about each supplement in the supplementenoverzicht.
You will receive the amounts needed to complete the 5 Day Fast program. They are fixed in the program and are not adjusted based on body weight, except for glycerol: that dosage is based on your body weight. This is clearly explained in the program you will receive.
So, every participant gets the same supplement structure for the 5 days. Just follow the provided instructions instead of adjusting the timing or dosage yourself.
The supplements have been selected to support the structure of the programme: from essential nutrients and fatty acids to supporting digestion and muscle function during a period with lower energy intake.
They make the programme more complete and practical. They aren't meant to replace a varied diet outside of the 5 Day Fast or to treat any medical condition.
During the programme, only use the 5 Day Fast supplements, unless your doctor prescribes otherwise.
Other supplements might contain calories, sweeteners, stimulants, caffeine or active ingredients that don't fit within the programme. After 5 Day Fast, you can usually resume your own supplements again.
Always take medication as prescribed by your doctor.
Never stop, reduce or change medication on your own initiative. If you use medication, have a medical condition or are unsure if 5 Day Fast is suitable for you, please consult your doctor or treating specialist before you start.
Only use what is included in the programme or what has been approved by the 5 Day Fast team.
Do not add extra products yourself, especially if they contain calories, caffeine, sweeteners or active ingredients. After 5 Day Fast you can resume your own supplements again.
Yes. The menu is completely based around plant-based foods.
If you want more information, or if you have any allergies, dietary restrictions or specific questions about ingredients, just get in touch with us before you order.
Results & losing weight
What you can realistically expect, and what you can't.
5 Day Fast can support various effects, such as a drop on the scales, less strain on your digestion, more awareness of eating habits and a temporary shift towards more fat use and ketone production.
The exact results vary per person. They depend on your starting point, how well you follow the programme and what you do after the 5 days.
No. 5 Day Fast is a structured 5-day programme, not a guarantee of a specific number on the scales. Weight loss, energy, sleep, hunger levels and sports performance differ per person.
Your results depend on your situation before the programme, sleep, stress, activity level, how closely you follow the programme and the phase after the programme.
Many participants see a drop on the scales during the 5 days.
Some of this is due to loss of glycogen and water, especially in the first few days. As the programme progresses, the body may shift more towards fat as an energy source, which could contribute to fat loss.
How much weight you lose and keep off varies from person to person. It depends on your starting point, how closely you follow the programme, and what you do after the 5 days.
Want to understand the difference between weight on the scales, water loss, and fat loss? Then read more about afvallen in 5 dagen.
5 Day Fast temporarily lowers energy intake and the amount of available carbohydrates.
That can help the body shift towards more fat use, ketone production and metabolic flexibility. That doesn't mean all lost weight is fat. Fat loss depends on your starting point, how well you follow the programme, your activity level and what you do after the 5 days.
5 Day Fast is designed to support fat utilisation and ketone production during a short period of energy restriction. As the body uses more fat and ketones for fuel, this may reduce the need to use amino acids as an energy source.
The programme also contains glycerol. Glycerol is naturally involved in energy metabolism and can serve as an alternative energy source during periods of lower energy intake. In that context, it supports the broader approach aimed at limiting muscle loss as much as possible during the 5 days.
Yes, and that's one of the goals. The 5 Day Fast helps make you more aware of hunger, habits, meal timing and food choices.
It doesn't happen automatically, though. The long-term effect depends on what you do after the 5 days and whether you use the experience to build better habits.
5 Day Fast doesn't guarantee better sleep.
Some people sleep better because they eat less later in the evening, put less strain on their digestion, stop having caffeine or reset certain habits. Others actually sleep worse during the 5 days, as energy restriction, caffeine withdrawal or stress can affect sleep.
Sport & training
Exercising during the programme and planning around a match.
Yes, you can work out during the 5 Day Fast. In fact, exercise is an important part of the programme, as it can help your body use stored glycogen and support the transition towards more fat burning and ketone production.
Keep the intensity low. Go for a pace where you can still chat comfortably, and shorten the duration if you need to. Walking, gentle cycling, light jogging or mobility exercises are a great fit.
The goal isn't to perform during the 5 days. The goal is to stay active in a controlled way, support the metabolic shift and avoid unnecessary stress. Avoid high-intensity sessions, long heavy workouts and heavy strength training during the programme.
With 5 Day Fast, you'll get movement suggestions for the 5 days.
You can follow these suggestions or use your own training plan, as long as the intensity stays low. The goal is light daily movement, not heavy training.
Walking, mobility, easy cycling, or a light jog work well. Choose a pace where you can still comfortably chat, and lower the intensity or duration if you need to.
Yes, but you'll need to adjust your training.
Preparing for a marathon, triathlon, Ironman or another event? Plan your 5 Day Fast during a recovery week or a lower-intensity phase.
Keep sessions easy and avoid high intensity during the 5 days. If you train daily, this planning is extra important so the programme fits into your training schedule rather than competing with it.
5 Day Fast can support mechanisms that are relevant for endurance athletes, such as fat oxidation, metabolic flexibility and glycogen sparing.
During the programme, training might feel harder. The potential gain for performance comes afterwards, as soon as normal nutrition, glycogen stores and training intensity are restored.
We explain this further in our article about 5 Day Fast, vetverbranding en duursport.
Don't plan your 5 Day Fast too close to an important race or event.
Finish your 5 Day Fast nine to sixteen days before a race, that way you'll have a good margin. Doing 5 Day Fast for the first time? Then take a bit more time, for example two to four weeks.
Heavy strength training is usually not ideal during the 5 days.
Light training sessions are okay, but the goal is not to build strength or push performance during the program.
Gradually build up heavier training again after the 5 days, as soon as nutrition, protein intake and energy are back on track.
Safety & contraindications
Who 5 Day Fast is and isn't suitable for.
No, 5 Day Fast isn't suitable for everyone.
The program temporarily lowers your energy intake and therefore asks quite a bit from your body. Don't start if you are pregnant, breastfeeding, actively ill, under 18 years old, or if you have or are recovering from an eating disorder.
If you use medication, have diabetes, a medical condition, a low BMI, or if you're not sure, please consult a doctor or treating specialist before you start.
Don't start if you are pregnant, breastfeeding, actively ill, have a fever, an injury, extreme stress or during a period of poor recovery.
Also don't start if you have a low BMI, an eating disorder, uncontrolled medical problems or if you're unsure about your medication.
In doubt? Then wait and consult a doctor or treating specialist first.
No, 5 Day Fast is not suitable during pregnancy or breastfeeding.
Pregnancy and breastfeeding increase the need for nutrition and energy. A period of energy restriction doesn't fit into these phases.
Wait until breastfeeding has finished and check with a healthcare professional if you're in any doubt.
Don't start the 5 Day Fast without medical advice if you have diabetes, use medication or have a medical condition that makes you doubt.
Changes in energy intake, carbohydrate intake and body weight can affect your blood sugar, your medication needs and how you feel.
Always consult your doctor or treating specialist first.
5 Day Fast is usually not suitable if you have a low BMI or are underweight.
The program temporarily reduces your energy intake. If your body weight is already low, this can pose an unnecessary risk.
Consult a healthcare professional before you consider a fasting-based program.
In many cases, women in the menopause or transition can consider 5 Day Fast, but your personal situation is important.
Energy restriction can be an extra strain. Are you already suffering from severe fatigue, poor sleep, hot flushes, a lot of stress, low energy or medical issues? Then discuss this first with your doctor or treating specialist.
Are you unsure about the timing? Then get in touch with us, so we can think along with you about the best moment to start.
Yes, you can do 5 Day Fast if you use hormonal contraception.
Your personal health, cycle-related complaints, medication use and medical history can play a part though. Are you unsure? Please consult your doctor or specialist before you start.
Don't change your contraception or medication because of 5 Day Fast without medical advice.
Do you have an eating disorder, are you recovering from one, or have you had an eating disorder in the past? Then we advise you not to do 5 Day Fast. If you think differently about this, please discuss 5 Day Fast with your doctor, dietitian, or treating specialist first. The programme involves a temporary reduction in food intake, and that might not be suitable for everyone.
For some people, the clear menu, shopping list, and structure help to reset eating habits. But could restriction trigger stress, control, guilt, or compensatory behaviour around food for you? Then 5 Day Fast might not be the right choice at the moment.
Are you in doubt? Don't make the decision alone and talk to a qualified healthcare professional first.
Comparisons
The difference with Sportvasten, intermittent fasting and water fasting.
Both have to do with fasting and metabolism, but they are not the same.
Sportvasten is usually built around a combination of dietary restriction and exercise. 5 Day Fast is a fasting mimicking approach with a structured menu, supplements, shopping list and guidance.
A key difference is the scientific basis. 5 Day Fast is based on the principles of research into fasting mimicking diets, where the goal is to mimic certain effects of fasting through a specific balance of calories, fats, carbs and proteins. Sportvasten is less standardised and can differ greatly per method, provider or coach.
Want a structured 5-day protocol with a menu, supplements and guidance? Then 5 Day Fast might be the more practical option.
For a full comparison, read our guide: 5 Day Fast vs sportvasten.
Intermittent fasting usually means you adjust your daily eating window, for example by eating within 8 hours and fasting for 16 hours.
5 Day Fast works differently. You don't follow a strict daily eating window. Instead, you follow a structured 5-day fasting mimicking menu with controlled nutrition, supplements and guidance.
During the day, you eat the meals and snacks from your menu without an intermittent fasting schedule. The structure doesn't come from restricting your eating window, but from what you eat, the quantities and the balance between the macronutrients.
Would you like to compare both approaches in more detail? Then read more about intermittent fasting en 5 Day Fast.
No, 5 Day Fast isn't the same as water fasting.
With water fasting, you don't eat anything. With 5 Day Fast, you follow a structured menu with controlled nutrition, supplements and guidance.
The goal is to mimic certain effects of fasting without completely cutting out food, making it easier to stick to than water fasting.
Read also what happens to your body during 5 dagen vasten.
Don't combine 5 Day Fast with intermittent fasting or other fasting methods during the 5 days.
The programme is already a structured form of fasting mimicking itself. Adding another fasting method might make the 5 days tougher and could cause extra stress.
Are you coming off another fasting period? Then make sure you gradually return to a normal eating pattern first before you start with 5 Day Fast.
No, 5 Day Fast isn't a crash diet.
A crash diet is usually about eating as little as possible to lose weight quickly. 5 Day Fast is built around controlled nutrition, supplements and a specific 5-day programme.
You might lose some weight, but the goal is broader than just the number on the scales.
After the 5 days
Building up, holding onto your results and training normally again.
After the 5 days, you'll focus on gradually building things up.
That means gently reintroducing food, restoring your protein intake, replenishing glycogen, getting enough sleep, and gradually returning to training.
The phase after the program is important, because it determines how much of the results you'll keep. We'll guide you through this phase as well.
Part of the weight might come back after the 5 Day Fast.
That is normal, especially when glycogen and fluid stores are replenished. It doesn't mean the program has failed.
Long-term results depend on your eating habits, exercise, sleep, stress and consistency after the 5 days.
Start with simple, nutritious meals.
Prioritise vegetables, proteins, healthy fats, fibre-rich foods and minimally processed products. Don't go straight back to heavy meals, overeating or old habits that you actually wanted to change.
Gradually return to training.
Light exercise can usually continue. You can build up heavy training again once your energy intake, protein intake, and glycogen stores are restored, after 7 to 9 days.
Athletes might want to avoid jumping straight back into high intensity if they still feel tired.
Get in touch with us before you start, via support@5dayfast.nl or the contact page.
It's better to ask questions beforehand than to adjust the menu yourself, add supplements, train hard, or start with a medical doubt.
Good preparation makes the 5 days easier to follow.
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