Juice fasting or water fasting?
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Time to read 6 min
Introduction
Juice fasting or water fasting—which form is right for you? Both involve going without solid food for a few days, yet they are worlds apart. With one, you consume only water and tea, while with the other, you receive some energy through juices. This changes how the days feel and how much support you need.
When comparing juice fasting and water fasting, we look at energy, muscles, safety, and daily life. You will learn the strengths and weaknesses of both methods and which one we recommend for getting started.
Good to know
With water fasting, you consume zero calories. Classic therapeutic fasting according to Buchinger ranges from 250 to 500 kilocalories per day. A juice cleanse like the BESSERE SAFTKUR PLUS provides 731 to 885 kilocalories according to nutritional information.
Juice fasting or water fasting? The short answer
For most healthy people, juice fasting is the easier way to start. You get some energy, vitamins, and fluids, and you can incorporate the cleanse into a calm daily routine. Water fasting is the strictest form of fasting. Because of the risks involved, it should be done under medical supervision and is better suited to a clinic than a normal work week. The choice between juice fasting and water fasting is therefore less about which is better or worse; it is about the framework and the experience.
In between lies therapeutic fasting according to Buchinger, which includes juice, broth, and a little honey. The Medical Society for Therapeutic Fasting and Nutrition (ÄGHE) recommends a maximum of around 500 kilocalories per day for this (ÄGHE, 2025).
| Feature | Juice Fasting | Water Fasting |
|---|---|---|
| Energy per day | approx. 500 to 900 kilocalories | none |
| What you drink | Vegetable and fruit juices, water, tea | only water and unsweetened tea |
| Support | possible alone for healthy people, medical supervision for underlying conditions | medical supervision recommended |
| Daily life | calm days are sufficient | rest or clinic |
| Typical duration | three to seven days | several days under supervision |
| For whom | beginners and experienced | experienced individuals with support |
What matters in the comparison
Energy and nutrients
The clearest difference is energy. During water fasting, your body relies entirely on its reserves. Within the first 24 to 48 hours, it depletes glycogen stores, after which it shifts more strongly to fat reserves (Swiss professional journal, 2022). With juice fasting, you get some sugar from the juices throughout the day, along with vitamins and minerals. This makes the transition smoother. The German Nutrition Society (DGE) sees the difference precisely here. With therapeutic fasting, the body still receives a little energy; with total fasting, none at all (DGE, 2018).
Our preliminary assessment 👈
If you are fasting for the first time, try juice fasting for three days. Water fasting is not for beginners; it is for experienced individuals under medical supervision.
Muscles and protein
When comparing juice fasting and water fasting, this is a point many comparisons leave out. Anyone who eats nothing at all loses more than just fat. A 2024 review evaluated eight studies on prolonged water fasting. Approximately two-thirds of the weight lost was water and muscle; only one-third was fat (Ezpeleta et al., 2024). At the beginning of a total fast, the body breaks down up to 75 grams of protein per day (Swiss professional journal, 2022). There is hardly any data on this for juice cleanses. This is another reason why short cleanses are the safer choice.
Support and safety
The same study notes frequent complaints during water fasting such as poor sleep, fatigue, dizziness, dry mouth, and headaches. Serious consequences, such as blood acidification or fluid retention in tissues, were rare (Ezpeleta et al., 2024). A large study of 1,422 people shows how much support matters. They were monitored daily by doctors and received 200 to 250 kilocalories per day. There were serious side effects in less than one percent of cases (Wilhelmi de Toledo et al., 2019). This is why water fasting should be left to experienced hands. Limits also apply to juice fasting. Pregnancy, breastfeeding, being underweight, eating disorders, and severe liver or kidney disease preclude any fasting (ÄGHE, 2025). Anyone taking medication should never fast alone. You can find the detailed checklist in our article on who is suited for a juice cleanse.
Both methods in direct comparison
Water fasting: advantages and disadvantages
Anyone weighing up juice fasting or water fasting should be familiar with the details of the stricter form. Water fasting is the oldest and most rigid form of fasting. You consume only water and unsweetened herbal tea and take in zero calories. In clinics, it is performed under medical supervision with regular checks. Its appeal lies in its simplicity; the price is the burden it places on the body.
Advantages:
- Maximally simple: You need nothing but water and tea.
- Zero calories: Weight drops faster in the first few days than with any other form.
- Clear rules: There is no question about what you can or cannot drink.
- Well-studied: There are more studies on supervised fasting than on juice cleanses.
Disadvantages:
- Significant muscle loss: About two-thirds of the weight you lose is water and muscle.
- Frequent complaints: Dizziness, fatigue, and poor sleep are common.
- Requires support: It is not advisable for many people without medical supervision.
- Hardly suitable for everyday life: Work and appointments do not mix well with zero calories.
Juice Fasting: Pros and Cons
During a juice fast, you drink several juices throughout the day, along with water and tea. Whether juice fasting or water fasting feels easier usually becomes clear by the second day. In this regard, a juice cleanse has a clear advantage. However, it has a catch you should be aware of: juices contain sugar and almost no fiber. A small study found changes in oral and gut flora after three days of consuming only juice. Researchers identified the sugar and lack of fiber as the cause (US study, 2025). This supports opting for short cleanses based on vegetables.
Pros:
- Gentler start: A bit of energy makes the first few days significantly easier.
- Vitamins and hydration: Vegetable juices provide vitamins that are missing during a water fast.
- Everyday suitability: You can work normally on quiet days.
- Doable on your own: Healthy adults without pre-existing conditions do not need a clinic.
Cons:
- Sugar in a glass: Fruit-heavy juices provide a lot of fructose, which is why vegetables are mandatory.
- Hardly any fiber: It is left behind in the pulp during pressing.
- Fewer studies: There is significantly less research on juice cleanses than on supervised fasting.
- No shortcut: Here, too, some of the weight returns after the cleanse.
Our article on calories and sugar in a juice cleanse shows how much sugar is in which juice.
Juice fasting or water fasting in brief
Water fasting is the strictest form and should be done under medical supervision
Around two-thirds of the weight lost during water fasting is water and muscle
Juice fasting is gentler and fits into quiet days in your daily routine
With juice fasting, the vegetable content determines the sugar level
For a start, try a vegetable-based juice cleanse over three days
What is the difference between juice fasting and water fasting?
In water fasting, you only drink water and tea and consume no calories. In juice fasting, juices are added, providing some energy, vitamins, and minerals.
Which is better, juice fasting or water fasting?
For beginners, juice fasting is usually the better choice because it is gentler and easier to integrate into daily life. Water fasting is stricter and requires medical supervision.
Do you lose muscle while water fasting?
Yes. In studies on prolonged water fasting, about two-thirds of the weight lost was water and muscle.
Do you lose weight faster with water fasting?
In the short term, yes, because no calories are consumed. However, a large portion of this is water and muscle mass, and without lifestyle changes afterwards, the weight often returns.
Can I do water fasting on my own?
This is not advisable for most people. Water fasting should be done under medical supervision, especially if you take medication or have pre-existing conditions.
Is juice fasting too sweet?
That depends on the juices. Fruit-heavy cleanses provide a lot of fructose; vegetable-based ones provide significantly less. Therefore, check the ingredients list.
Who should not fast at all?
Fasting is not suitable during pregnancy and breastfeeding, for those who are underweight, or for those with eating disorders or severe liver or kidney disease.
The Author: David J Kugler
Founder and Managing Director of DALUMA. Writes about nutrition, juice cleanses, and holistic self-care.
