A juice fast is a temporary change in food habits where we replace regular meals by simply juice, no pulp. It lasts anywhere from 1 to 60 days. A small fraction of people do even longer juice fasts. Fasts are different from diets. Fasts are temporary measures whereas diets are permanent in nature.

My understanding is that 'water fasting' for a small number of days is the traditional method of fasting worldwide. During a water fast, one consumes only water. Rest is important, both physically and mentally. A variant of water fasting is 'honey lemon fasting', as advocated by Dr Manthena Raju from Andhra Pradesh, India. This article explains it in detail.

In the modern world, with the invention of juice extractors, we have discovered the concept of juice fasting, where we consume only juice! Now juice has lots of calories. So there is no need to rest physically and mentally. In fact, juice can sustain regular, buoyant life for surprisingly many days!

Benefits of Fasting: Traditionally, fasting has been considered curative and therapeutic. The article Benefits of Fasting (1977) by Paul Martin traces the history of fasting in various cultures. Modern Western medicine does not associate fasting with significant health benefits. See Wikipedia article on Fasting, for example. Proponents of fasting point out that there is no money to be made by pharmaceutical, chemical and food industries So there is no economic or industrial incentive to study fasting — why study a phenomenon which reduces consumption?

In Feb 2012, a friend posted a positive review of a documentary called Fat, Sick and Nearly Dead (97 min, 2010) on FaceBook. The title may sound negative. However, the movie is very uplifting, very inspiring. Watch "Fat, Sick and Nearly Dead" for free at RebootWithJoe.

Summary: The documentary showcases the personal story of Joe Cross, a rich Australian businessman who cured himself of a rare autoimmune disorder that plagued him for nine years. The movie is down to earth, honest and inspiring. For his 60-day juice fast, Joe took a break from his business, flew to USA and drove from coast to coast in a Mercedes convertible. Along the way, he shot his own videos and interviewed random people in restaurants, bus stops, parks, and so on. The movie shows Joe's health improvements with every passing day. It also shows a sampling of American belief about food and health.

Dr Fuhrman: The physician who guided Joe's 60-day fast was Dr Joel Fuhrman, a prominent advocate of Plant Based Diets. He is among the few Western doctors to have authored a book on fasting: Fasting and Eating for Health (255 pages, 1995).

My second inspiration was Kabir Kumar. A FaceBook comment pointed to his blog. I realized that juice had sufficient nutrition to allow a regular life. I also realized that one could do a juice fast without medical supervision. In November 2012, Kabir gave an awesome TEDx Talk (7:10), narrating his juice fasting experiences. Kabir's TED talk focuses on weight loss. He also mentions mental clarity and calmness, which are commonly reported by those who fast.

A blurb on weight loss: I implore my friends that instead of making weight loss a goal, they should commit to healthy lifestyle habits. Then weight loss is a 'side effect' — it comes for free! Those who intend to do a juice fast for losing weight, only to return to unhealthy eating and exercise habits, are missing the point. Please see juice fasting as an opportunity to pick up awesome lifetime habits.

Three factors motivated me to do a ten day juice fast:

(a) Cleansing / detox: Two pieces of information convinced me that concepts like cleansing and detox were relevant to me:

1. The first time that I had heard of phrases like "detox fasting" or "detox diet" was during a 10-day Vipassana meditation retreat in September 2007. A bunch of students from different parts of USA were using these terms in their discussions. I picked up the acronym SAD which denotes Standard American Diet, a pejorative term used for diet dominated by steaks, burgers, fries, pizzas and sodas. In 2007, I had imagined that such cleanses were for really sick people. Five years later, in 2012, I learnt that many health advocates in USA consider regular food so unhealthy that they recommend cleanses for everybody on the Standard American Diet.
2. In ancient Indian traditions, the term ShatKarma denotes yogic practices for cleansing our bodies. One of these practices is called basti kriya. It is for cleansing our colon.

(b) Cure from viral infection: I started my juice fast in the midst of a bad viral infection. My major symptoms were persistent sore throat and intermittent coughing, which had lasted almost ten days. Online articles mentioned that fasting is curative. At the same time, I wondered if it made sense to do a juice fast when I was sick. I had never done this before. I resolved the confusion by convincing myself that I was pretty strong, so a juice fast when I was moderately sick would be just fine for me.

(c) "Reboot my diet": I had a strong belief (I kinda 'knew') that after my juice fast, I will have awesome, healthy food habits. I didn't quite know what I would eat because I didn't know what healthy eating meant :) But I had ten days to figure that out.

(d) Curiosity: Online articles made it sound like something mysterious, something magical, something spiritual, something that western science does not understand. That aroused curiosity in me: I was eager to experience the effects of a juice fast, just for the heck of it :)

What juicer to buy? Amazon's list of Best Sellers in Kitchen Small Appliances includes juice extractors. In a juice fast, we drink just juice; we do not consume pulp. A 'juice extractor' will separate juice from pulp whereas a 'blender' will make a smoothie with juice and pulp mixed together.

I first thought of buying a cheap $35 juicer with good reviews. Later, as I browsed around the web for juice recipes and juicing articles, Breville caught my attention. So I bought a Breville BJE200XL Compact Juice Extractor. In Feb 2012, buying directly from Breville's website was cheaper than buying from Amazon.

What is the composition of juice? The success of the movie 'Fat, Sick and Nearly Dead' inspired a website called Reboot With Joe. One of the sections at this website is juice recipes. I browsed through all the recipes and concluded that basically, I need some mixture of green vegetables, fruits and roots. No nuts. Citrus fruits are to be generally avoided unless you have cold. Roots like ginger and turmeric are awesome. I learnt that we could also add raw yams. On the third or fourth day, I added avocados and raw coconut too.

[Update in 2019] Dr Fuhrman's article on juicing explains that juices should primarily be composed of vegetables, not fruit.

[Update in 2019] A friend once bought a 6-pack 'juice fasting pack' from a company specializing in cold pressed juices. I noticed that one of the juices was more like a 'diluted nuts n dates smoothie' instead of a juice. Its primary ingredients were almonds and dates. Note that a juice fast centers around vegetables (and a little bit of fruit), not around nuts and dates.

Making your own juice with organic ingredients is important. Organic food in California is found in local Farmers Market or Whole Foods. Juice sold in bottles and cartons is full of chemicals. For those who need convincing, please read Squeezed: What You Don't Know About Orange Juice (288 pages, 2010) by Alissa Hamilton. The gist of the book lies in this article: Book Review of Squeezed. A 5-minute video in which Alissa Hamilton explains her key findings related to packaged orange juice.

Juice storage and many other questions: I found two resources. First, Juice Fast Experience is a wonderful article with answers to many practical questions. Second, RebootWithJoe FAQ (YouTube Playlist) has 18 short videos in Q&A format. Doing Less and Accomplishing More: A Technique for Successful Fasting is another good article.

Books and videos: I discovered two wonderful resources several months after my juice fast:

Fasting - Safe and Effective Use of an Ancient Powerful Healing Therapy (55 minutes) by Dr Michael Klaper. This is an awesome video by a medical doctor who supervises fasting. The video answers many questions like: how many days should we fast? what symptoms should we expect? when should we break a fast? who should fast? who should fast only under medical supervision? If you have a medical condition, then you must definitely watch this DVD before you do any sort of fast.

Fasting and Eating for Health (255 pages, 1995) by Dr Joel Fuhrman. He is the doctor who supervised Joe Cross' juice fast. Joe Cross is the hero of the documentary 'Fat, Sick and Nearly Dead'. Dr Fuhrman is an advocate of Plant Based Diets and one of the few medical doctors who has authored a book on fasting.

Supervision: All websites for juice fasting, including the movie 'Fat, Sick and Nearly Dead', recommend doing the fast under supervision. This is especially important for people with ailments. I didn't approach any supervisor, doctor or nutritionist for my fast - I did it myself, gung ho! My plan was to visit a doctor if something surprising came up or if I felt really sick. I was kinda confident that since I'm generally healthy, I should be able to fast without any problems. Through online reading, I learnt of two issues for which a supervisor would be very helpful:

1) Healing Crisis: During multi-day fasts, people experience a phenomenon called "healing crisis". A slew of symptoms makes you feel really sick. However, the body is not sick; it is healing itself. A seasoned supervisor can help you distinguish between "healing crisis" and real illness.

2) It's important to come out of a fast properly. We cannot suddenly eat regular food after consuming only juice for many days. I still don't know the right sequence of steps to make this transition. I could not find a website or an article where the process of gradually shifting to regular food is described adequately. I used my intuition and it took me about five to seven days for my stomach to start feeling normal.

Day 1: Most websites suggest consuming 80 oz of juice per day. On the first day, I consumed about 120 oz of juice! I felt really full.

Day 2: I had proper bowel movement and plenty of stools. I was surprised where all this was sitting inside my body because I had eaten nothing solid for one day.

Day 3: I had no stools, just gas in my stomach. On two occasions, I had bowel movements with diarrhea. During one of these, some blackish material came out of my body. I feel weaker than normal. Was the blackish material the dirty stuff that my body was cleansing? In hindsight, this was the worst day out of the ten days.

Day 4: In the morning, I had some bowel movement. Some not so good looking stools. Not black but blackish. I didn't feel hungry.

Day 5: I did not feel like consuming juice at all. I had herbal tea and honey (about ten spoonfuls of honey in the whole day). So it was like a 'water fast' but with honey. By the fifth day, my viral infection symptoms had subsided significantly. But I was feeling weak. I'm definitely not looking good.

Day 6: Didn't feel like consuming juice again. Just herbal tea with honey throughout the day. Still feeling weak. Bowel movements in the morning: watery and greenish black stools.

Day 7: Resumed consuming juice. Within an hour of consumption, I felt so much stronger! Some stool movement. This was the first day that I went out for a four mile walk around a lake. So far, I'd been resting at home.

Day 8: Went well. Feel good. Have recovered from my viral for sure. Intuition suggested that my stomach had cleared up and that I could break my fast now. But since I had committed to ten days, I decided to continue for another two days.

Day 9: Went well. My face felt smoother for some reason. I also felt that I'd lost some fat tissues in the face region. I was probably skinnier than before. But I felt energetic and quite healthy as well.

Day 10: Went smoothly. Felt good.

Mistakes:

1) Lack of water: I was sipping juice all day long, without rinsing my mouth. Also, I did not have any water. Later, I learnt that juice fast does not mean that I should have stopped drinking water. By day nine, I felt pain in my gums. My intuition said that this was some combination of dehydration and acidity in the mouth because I was not rinsing regularly. In two days, the pain subsided and my gums felt healthy again.

2) How to break a fast? Till date, I don't know of good strategies for coming out of long juice fasts. What sequence of foods should we consume on successive days so that our bowel movement stabilizes within a few days?

On the fourth and fifth days, I started discussing basic questions related to food with a friend using Google Chat. Do we need to eat fruit? Yes. Do we need to cook fruits? No. Do we need oils? Not if we eat seeds and nuts, from which we derive oils. Do we need to heat oils to high temperatures? No, we can eat oils just like that. Do we need to cook vegetables? Yes, some of them. Do we need food guidelines in terms of invisible substances like proteins, carbohydrates and fats? Can we have food guidelines in terms of real foods? And so on. Very basic questions. And I sought simple guidelines, without complicated, scientific words.

In response to my questions, my good friend remembered Dr John McDougall. He pointed me to his Healthy Eating Guidelines. For that pointer, I am deeply indebted to him! As I browsed through McDougall's guidelines, I realized that he addressed all of my questions in plain English, without using any complicated terms! From McDougall's books on Amazon, I discovered other doctors like Neal Barnard, Dean Ornish, Caldwell Esselstyn, Gabriel Cousens and Joel Fuhrman! Soon, I discovered that all of these doctors were saying pretty much the same thing. A few months later, I summarized my findings in a lengthy article titled "Plant Based Diets".

For almost three months, I adhered to very strict guidelines: no meat, no dairy, no fried food, no refined sugars, no alcohol, minimal spices, and so on. The benefits were tremendous! I felt a great sense of peace inside myself. I had experienced such peace only after 10-day meditation camps. That food habits could influence my peace level to such an extent was a surprise to me. About six weeks later, I connected the following dots: Basically I was eating a Sattvik diet, which is chosen by saints and sages in the East for becoming calm and peaceful. Please don't imagine that I became as calm as Buddha. That's far from true. However, there was a significant shift, a palpable change in me. It reflected in how I related to others and how I reacted to situations I faced.

Physical changes: My weight fell from 162 lbs to about 152 lbs within ten days. Over the next one year, my weight stabilized to a narrow range: 147 lbs to 151 lbs.

A prominent physical change that I felt was in my stomach area. My stomach muscles were much more relaxed by day eight. I remember telling a friend about this change on day eight. Many months later, I attended a stress reduction class at Google conducted by Fred Luskin, a psychologist from Stanford University who is famous for research, books and classes related to forgiveness. One of the techniques he mentioned was to consciously relax your stomach muscles many times during the day. According to Fred, we all carry tension in our bodies, especially in our stomach muscles. Relaxation of our stomach muscles is a powerful stress reduction exercise.

Other physical changes were not exactly a consequence of the juice fast. They were associated with the transition to plant based diet. (A) My stools became high quality after the transition. (B) My skin felt smoother. This is something that women aspire for, so I am mildly embarrassed to report this. But it's true. (C) I restarted hiking within a week of finishing my juice fast. I noticed that I was breathing much better. Somehow, the air in my lungs and in my chest felt much fresher! Later, some friends told me that this effect is associated with dropping milk from one's diet. (D) Six months later, I discovered that my cholesterol numbers were excellent: total cholesterol was 99, LDL was 40, HDL was 45.

Mental calmness: The most significant change I felt after my juice fast was mental calmness and clarity. For me, it was equivalent to doing a 10-day Vipassana meditation retreat. In the East, we have phrases like 'jaisa ann, waisa mann' (like food, like mind). I can vouch for this aphorism from personal experience now. In the Western tradition, there is very little research on relationships between food choices and our calmness levels. It is not zero though. For example, a few studies have been conducted on prison populations and school children. They have shown that removal of unhealthy food choices and introduction of healthy food choices leads to fewer incidents of violence and violations.

In October 2012, the first ever study that associated psychological well being with food choices was published: Is Psychological Well-being Linked to the Consumption of Fruit and Vegetables? by David Blanchflower (wikipedia page), Andrew Oswald (wikipedia page) and Sarah Stewart-Brown. This study was conducted by two economists and a public health professor. They found that among 80,000 British adults, psychological well being peaks at about 7 servings of fruits and vegetables per day.

Further research exploring the relationships between fasting, plant based diets and psychological well being would be awesome!

Sending you good wishes for a wonderful fasting experience!