Select Page

Fasting With Juice

by | Jun 5, 2020 | FASTING METHODS | 0 comments

The Big Idea 

What could possibly be better than concentrating a week’s worth of fruits and veggies into a day of delicious drinks that saturate your body with much-needed antioxidants and immune-boosting compounds? Well, it turns out nothing would actually better. As in – eating and drinking ‘nothing’.

Compared to the robust research on fasting, juice fasting boasts only one study with a very limited scope and scant results. But looking past the science for a sec, juice fasting has been an important part of health culture for decades, and there are plenty of anecdotes on how it can improve health conditions from gastroenteritis to cancer, even.

Though not the holy grail of fasting, juice cleanses can be a great way to break into fasting while significantly upgrading your nutritional status.

What it is

Juice fasting is somewhat of a misnomer because there are plenty of calories in an average juice cleanse: typically 800-1200 in a day. This extra energy would be enough to disrupt the main benefits of fasting such as autophagy and insulin reduction.

Juice cleanses, then, can be considered as therapeutic nutrition that harnesses certain aspects of fasting – namely protein restriction and no actual food – for health improvements. They typically last from 1-3 days (though some go up to two weeks), and they consist of


  • fresh-pressed fruit and vegetable juice – apples, carrots, pineapples, kale, celery, lemon, etc.
  • and occasionally nut butters or milks, which make for a more substantial meal. 

The concept of juice fasting was originally developed in the 1930’s by Norman Walker, was later popularized by Jack Lalanne, and is carried on today by health icons such as Kris Carr and David Avocado Wolfe and Joe Cross. Most doctors and dieticians consider it to be a generally healthy habit in moderation.



Our nutrition today, though we eat far more than we did half a century ago, is inferior to people of that same era. This is due to modern farming practices that have destroyed much of the mineral content in our soil. (Studies show that we get 6% to nearly 40% less of key minerals and nutrients because of soil depletion.)

Yes, we take our supplements. But supplements lack cofactors and enzymes found in whole plants that increase the vitamin or mineral’s usability in our bodies. This makes juice fasting an appealing option for anyone looking to bolster their nutritional status and improve their health without taking a pill. 

May promote longevity

Whether full or partial, there’s one thing that all science-backed fasts have in common: protein restriction. This protein restriction appears to be one of the most significant factors in why fasting is so good for us because protein restriction generally reduces the production of insulin-like growth factor 1 (IGF-1). And a lack of IGF-1 is strongly correlated with a longer lifespan.

Even though juice fasts can contain substantial calories, they’re all typically very short on protein. This can be a healthy thing when done periodically and not for periods of longer than three days.

Nitric oxide

Certain vegetables that are juiced, namely beets, can produce high amounts of nitric oxide (NO) in the body. The main study was done on juicing confirmed this, showing impressive increases in circulating NO after just three days of a juice fast.

Nitric oxide is a vasodilator, meaning it expands your blood vessels. This expansion allows for more blood flow, which is associated with cardiovascular protection, and even better athletic performance.


The risks for a juice fast are pretty minimal, especially if the fast is done for shorter durations.

One of the main concerns is that high doses of sugar without any fiber could lead to spikes in blood sugar levels and potentially exacerbate symptoms of diabetes and metabolic syndrome. These fluctuations in blood sugar can also cause headaches, tiredness, and fatigue.

For those who don’t have properly functioning adrenal glands, juice cleanses can also cause a dangerous imbalance in your salt-to-potassium ratio. Most of the fruits and vegetables you juice will be very high in potassium and very low in sodium. If your body pumps out salt due to adrenal issues, this influx of potassium can cause confusion, headache, nausea, muscle cramps, or spasms.

How to Do it

Prepare your body with a few days of light eating

One of the quickest ways to get an unpleasant juice-fasting experience is to eat a bunch of heavy foods and a ton of calories the day before your fast. Instead, go light in the day (or days) preceding, opting for choices like soups, salads, and fish if you need protein. This will help you get more cleansing benefits by not having your digestive system burdened with processed foods and heavy meats.

Consume six 16-oz glasses of juice per day

Experts recommend consuming six 16-oz glasses of juice per day at least. This adds up to about one glass every couple of hours or so.

Though there are plenty of juicing companies and probably some in your neck of the woods, pre-made juices tend to be higher in fruit juice and lower in vegetable juice. This is not recommended, mainly because of the excessive sugar content. If you are able, opt for mostly vegetable juice blends.

Also, go organic if at all possible.

Have sea salt on hand

If you start to get a headache or feel a little woozy, try taking a pinch of sea salt or mixing in half a teaspoon in a glass of water. This will help balance your electrolytes.

Go light on exercise

Juice fasts are not the time to kill yourself at the gym. Even though you’re consuming more calories than traditional fasts, you’re not getting any protein and your only getting ½ to 1/3rd your normal calorie intake – which is not enough to support recovery. If anything, take a few brisk walks, do a light cardio workout, or do some bodyweight exercises at home.

End your juice fast with light food 

For the same reason that you don’t want to kick your fast off with a heavy meal, you don’t want to break it with one either. Even after only a one-day fast, your digestion will have slowed down to handle the very easy job of breaking down juice. If you throw down with a ‘steak and taters’  dinner directly after your fast, you’ll likely experience stomach upset and indigestion.

Toast, crackers, kitchari, rice, salads, and soups are perfect foods to break your juice fast with.

List of Top Science or Studies:

Juicing increases NO and enhances gut microbiome

Key Experts:

Valter Longo, PhD

Joe Cross

As a celebrated health and wellness leader, Joe Cross inspires others to get healthy and lose weight through juicing and eating more plants and vegetables.
Joe first became known for his personal journey of weight loss through a juicing lifestyle that lasted 60 days.

Joe transformed from being obese and sick with a crippling autoimmune disease to losing weight and feeling his best. He now has programming and products and offers a number of offerings under the Reboot brand.  He is well known for his role in the award-winning documentary film “Fat, Sick & Nearly Dead,” which has been seen by more than 30 million people.

“Instead of thinking about how to punish ourselves, we should be focusing on getting things back in balance.“

“You don’t get permanently well unless you permanently change the way you live.”

Kriss Carr

Kriss Carr

Kris Carr has been recommended by prolific wellness author Dr. Mark Hyman for her juicing knowledge. Here’s what she had to say in an article on her website:

“You may be wondering why anyone would go through all that trouble. Absorption, baby. Since your body doesn’t have to work to digest the fiber, it can easily pull the vitamins, minerals, and phytonutrients straight into your bloodstream. Plus, giving your digestive system a break means your body can focus on resting and repairing your hard-working cells.”

David Avocado Wolfe

David Avacado Wolfe

David Avocado Wolfe is a natural foods evangelist who recommends juicing, even outside of the juice-fast context. “I love green vegetable juices like celery/cucumber/lemon,” David said. “Here’s what I love about them: there are no calories, there’s no sugar, and there are no stimulants. But if you drink that thing…you have energy, baby.”

About The Author

Fast Forward Editors

Your go-to-crew for all things fasting and lifestyle. is digital destination for the latest science, strategies, solutions and stories to help the public discover and uncover the benefits of fasting, answer all of their fasting questions and find the best next step and resource to get started. Logo

Give your body (and inbox) a break!

Just the essentials to keep you successful in your fasting journey.

You have Successfully Subscribed!

Just for you!

Based on the content you're viewing, our newsletter would be a great fit.

We're looking forward to seeing you soon!

Pin It on Pinterest

Share This