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Why I Developed The 3-Day Flash Fast: The Easy, Fun Way to Fast

Robyn Openshaw, MSW - Updated: September 25, 2020 - - This Post May Contain Affiliate Links

Photo of open Flash Fast kit box showing individual mini meals and fasting booklet from "Why I developed the Flash Fast" by Green Smoothie Girl

When I was a young girl, my 8th birthday meant I could join my family in a religious rite of passage where we all fasted for 24 hours on the first Sunday of the month.

We got dressed up and went to church for 3 hours, but with no breakfast or lunch. When we got home, we were not allowed to watch TV or read worldly books; instead, my 7 siblings and I were encouraged to engage in reflective, spiritual practices, such as writing letters or reading scriptures.

Griping, or talking about hunger, was discouraged. In my family, we weren’t even allowed to drink water during the 24-hour monthly fast. In modern times, this is called “dry fasting,” though we didn’t have that word for it when I was a kid.

[Want an easy way to gain the benefits of fasting without the struggle? Water fasting is hard. Flash Fasting is easy. Right now, you can save 50% on three 3-day Flash Fast kits, during our Annual Group Buy. This is the best deal we've ever offered on the Flash Fast!]

In this article:

My History With Fasting

The purpose of my family's monthly fast was to be obedient to God’s commandment to fast, as well as to humble the physical body so that we could discern things of the Spirit with more sensitivity. After all, when you fast, you lose a lot of your energy provided by food/calories, so you're required to be more still. And there’s a sentiment that spans many religions, as well: that in suffering, we become closer to God.

Photo of Mature Asian woman putting two hands together and praying at home from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
Spiritual fasting is used in many religions to bring one's self closer to God.

I struggled with fasting as a kid. In fact, of the 8 children in my family, three of us (myself, plus my brothers Spencer and Russ) all had hypoglycemia, a blood sugar problem probably caused by a combination of heredity and eating processed sugar.

Sometimes one or more of the three of us couldn’t get through the 24 hours without passing out or becoming ill. And when we became very weak and unable to function, we were given food—but we felt like failures. Or at least I did.

Clinical Water Fasting

Many years later, I would learn that in addition to enhanced spirituality, there are many emerging, documented physical health benefits of fasting. I learned that what I’d done as a child might be the best health-preventative practice1 there is, better than any nutrient IV or biohack or session in a sauna.

Luckily, fasting wasn’t foreign to me, due to my upbringing in a religious faith where fasting is a cornerstone. It was still a little bit scary, considering how much trouble I had with fasting as a kid, though I continued to fast throughout adulthood as well. I stabilized my blood sugar2 as an adult when I stopped eating processed sugar on an empty stomach and ate much less of it overall.

But about the time I turned 50, having read extensively on the phenomenal benefits of fasting,3 I was intrigued about doing a more serious experiment for more than just a day—and I sought out a fasting clinic.

Hindu Water Fasting Retreat and Clinical Water Fasting

Over the course of 3 years, I flew four separate times to a Hindu ashram in Texas that hosts a number of different types of retreats, including silent retreats and fasting retreats. My four fasts at the ashram have lasted 7-12 days each.

I say the ashram “hosts” the fast rather than “leading” them because no one really checked in on me, for the most part, to do basic tests like blood pressure and heart rate or ask me how I was doing.

The ashram is in rural Texas, and there's no medical personnel there or anywhere nearby.

Photo of Texas yellow wildflowers landscape from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
The ashram in Texas is far from anywhere, making it impossible to break your fast by Ubering to a food joint.

I’ve come to think medical supervision is important if you’re going to water fast for a long period of time, so at this point, I don’t recommend anything but True North in Santa Rosa, California if you’re going to undertake a long-term water fast (more than a few days).

Although I hadn’t checked them out in detail before my four long fasts in Texas, it turns out it’s very inexpensive to get a room at True North for your water fast. You can check out my interview with one of True North’s founders, Dr. Alan Goldhamer if you're curious to know more.

My Water Fasting Experience and Results

Frankly, those long water fasts were miserable. I’d love to tell you that I had transcendent, emotionally cathartic, or spiritual experiences. I tried to remain open to that, and I went to the Hindu meditation every morning, along with yoga classes on most days.

But really, I mostly just struggled to get through each day, gutting it out because I knew I was doing something important and restorative for my health. Luckily, there was no food available. The ashram actually served three meals a day, but the monks and nuns make just enough for those who are there doing yoga or meditation retreats. Crashing a meal would seem rude and invasive, so it’s not really a temptation.

They ask that you let them know 24 hours in advance if you want a meal, so you can’t just show up for lunch one day, and say, “I’ve had it, can’t do this anymore—can I eat now, please?” This, and the fact that my Uber and Lyft apps didn’t work in that rural area, and the fact that there are no stores within walking distance, removed all temptation—and eliminating temptation is half the battle.

Photo of glass of clear water on white background from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
My water-only fasting was challenging; it's not for everyone (but the benefits can be).

So I gutted out the other half of the battle (hunger and weakness) and felt pretty proud of myself as each time I finished a fast and drove the 2 ½ hours back to the Dallas airport to fly home to Utah. But as a teacher, influencer, and educator, I always had the thought, “I’m not sure how to talk to my audience about this, because I don’t think even one in a thousand would do this.”

People seemed fascinated by my journey—thousands showed up for my Facebook Lives during my fasts—but mostly out of curiosity, apparently, because except for the rare, brave soul who tackled a one-day fast, nobody ever told me they wanted to do what I was doing.

But then I made a huge breakthrough in my awareness and journey.

New Research Emerges on Health Benefits of Modified Fasting

In January of 2018, Valter Longo, PhD’s book The Longevity Diet was published, and I read it—three times. I began to discover the emerging field of research in what I call modified fasting.

Longo and Brandenhorst, researchers at USC, have conducted many ambitious clinical trials on modified fasting.4 Based on what they’ve learned from previous animal studies, they allow their subjects to eat several mini-meals a day, staying under a certain number of calories.

Their groundbreaking work, along with additional data from other research institutions such as True North and Johns Hopkins, has uncovered phenomenal health gains.5 A modified fast is what most people around the world, forever, have benefited from, due to periods of scarcity most people don't experience in today’s Western world.

That is, Longo and Brandenhorst discovered the benefits of cycles of a calorie-restricted, plant-based diet for a few days at a time.

Continued Research on The Benefits of a Modified Fast

Longo and Brandenhorsts’ clinical trials keep rolling out, with spectacular results for multiple sclerosis,6 cancer,5 reversing the aging clock,7 memory loss, and many other specific health conditions that are epidemics these days in the Western world:

  • Myelin Sheath Regeneration: The new research shows that modified fasting supports the body's rebuilding of myelin sheath,6 which is potentially game-changing for MS patients, and something Western medicine has never accomplished, not even close. Western medicine has absolutely no tools to rebuild the myelin sheath in the nervous system—but the miraculous human body does.
  • Diabetes Reversal: Cycles of modified fasting reverse both Type I and Type II diabetes,2 regenerating insulin-producing beta cells.
  • Stem Cell Production And Anti-Aging: The body’s stem cell production goes quantum when you fast, rivaling the injections that North Americans line up to pay thousands of dollars for in anti-aging clinics. And with fasting, stem-cell proliferation8 occurs everywhere in the body, not just at the injection site.
Illustration of stem cells uses from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
Stem cells grow and specialize at a quicker pace while fasting.
  • Blood Pressure and Cholesterol Improvement: Published evidence shows that cardiovascular health is improved,9 and quickly, with modified fasts, as blood pressure comes down into normal range. Total cholesterol drops dramatically, and CRP (c-reactive protein), the major marker of systemic inflammation, also comes way down.
  • Improved Chemotherapy Outcomes: The newest clinical trial coming out of USC this year proves the cancer thesis that grew out of animal studies is also true with human subjects. That is, with a 4-day modified fast before doing chemotherapy, three particular benefits give great hope to cancer patients.5 One, fasting makes cancerous growths more vulnerable to chemo. Two, fasting causes healthy cells to put up a shield of sorts, to be more impervious to that same chemical cocktail. And three, fasting mobilizes the immune system to clean up and strengthen the system to survive and recover from the chemical assault intended for the cancer.
  • Sustained Weight Loss: Not only do subjects lose weight10—all of them, categorically—by doing a modified fast, but they tend to keep the weight off. Our own trial showed an average weight loss of 4 pounds, which means that the average person with significant weight to lose could lose 48 pounds in a year, just by doing a modified fast 3 days out of each month.

Modified Fasting for Benefits of Autophagy

Japanese researcher Yoshinori Ohsumi recently won a Nobel Prize in Medicine3 for his discovery of the mechanisms of action in the “self-eating,” or autophagy, that occurs in each cell, each organ of the body. This happens when you fast, or even when you do a modified fast.

Illustration of cellular autophagy function from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
This 3D illustration for Yoshinori Ohsumi's 2016 Nobel Prize Award in Medicine shows the mechanism of cellular autophagy – the fusion of a lysosome with a autophagosome, containing microbes and molecules.

This discovery, this science on modified fasting, is very, very new. And it’s incredibly exciting. It means that anyone and everyone can, without suffering, tap the body’s power of stripping down bad, broken parts—and rebuilding with new, quality materials.

In short, the discoveries about the power of modified fasting are more exciting and revolutionary than anything I’ve discovered in the 21st century so far.

Modified Fasting is Easier, With the Same Benefits

After the miserable experiences of water fasting for a week or more, modified fasting was a revelation to me. Perhaps I didn’t have to take 5 to 10 vacation days every year to do something I’d come to dread.

The discovery that I could do a modified fast and potentially achieve all the health benefits—it has been nothing less than life-changing.

This information is transformative, not only in my personal experiments and my vision of how I could use this practice to stay healthy, in this unprecedented, extraordinarily toxic world but also as a researcher and influencer, bringing my best discoveries to my audience online.

Because while virtually no one these days will tough out eating no food for a week, with a bit of preparation, guidance, and in the right macronutrient ratios, you can eat small amounts of nutrient-dense, plant-based food several times a day. Do it right, and just about anyone can achieve the benefits of fasting.

[Related: 9 Tips For Sailing Through A 3-Day Modified Fast]

Not only did I want to do my part spreading the exciting news, but I also wanted to figure out exactly what we could eat, in what portions, that would create the most satiety and the least hunger.

I wanted to simplify modified fasting and make it accessible and even painless for those who want to try it, whether they're doing a monthly 3-day fast primarily for weight loss (animal studies show autophagy targets belly fat specifically, and fat deposits in general) or a quarterly fast as a general disease preventative.

3-Day Modified Fasting Kit: The Flash Fast is Born

After a great deal of planning, testing, and collecting feedback, the Flash Fast was born.

Photo of open Flash Fast Box with produce and striped hand towels from "Modified Fasting 101: The Ultimate Beginner’s Guide" by Green Smoothie Girl
The GreenSmoothieGirl Flash Fast is a three-day kit with organic ingredients — and it's affordable.

I had seen one previous modified fasting kit, the only one developed at the time I developed our organic Flash Fast kit. This pre-existing 5-day modified fasting kit kept within the known science; it was plant-based and under 800 calories. But I wasn’t very happy with it on several other levels. It wasn’t organic, it had strange ingredients I consider to be toxic, and it was extraordinarily expensive.

In fact, you could eat in a sit-down restaurant, three times a day, for the price of the food in each kit. Some people were reactive to some of the foods in the kit that are common allergens.

I wanted to solve all those problems.

Elements of the 3-Day Flash Fast: What to Eat

I wanted modified fasting to be affordable, convenient, nourishing, and effective, so more people would be able to stick with it and enjoy the benefits.

  1. Calories: The research shows4 that plant-based foods achieve amazing disease-reversal, belly-fat-blasting, and memory-recovering results as long as the total caloric intake stays at 800 calories a day or less.
  2. Healthy Proteins And Fats: I knew that for satiety, a somewhat higher percentage of protein than most vegans get in their diet would be best, within the caloric restrictions. The program I developed needed enough fats, and they should cover the range of omega fatty acids and be the most high-quality, whole-foods fats available. This way, if people experienced higher satiety with their mini-meals, they could fast longer and go deeper into that important state of autophagy than they would if they ate the typical vegan’s high-carbohydrate, low-protein, low-fat diet.
inline ad flash fast benefits green smoothie girl
  1. 3-Day Fasting vs. 5-Day Fasting: I learned in my testing and research that over 95 percent of modified fasters are successful in completing a 3-day modified fast, but fewer than 20 percent are able to stick with it for a 5-day fast. How come? Our test groups said that Monday through Thursday is easy, but Friday through Sunday is more difficult because of weekend outings and social life.
  2. Whole Foods: We can’t ship fresh vegetables and fruit as part of the Flash Fast package, but we encouraged our test subjects to add up to 2 servings of non-starchy vegetables, and/or 1 serving of fruit, to their daily schedule of 5 mini-meals. This still kept them under 800 calories, but it added fresh, high-enzyme food and bulk.
Photo of Green Smoothie Girl's Flash Fast green box and food items laid out from "Modified Fasting 101: The Ultimate Beginner’s Guide" by Green Smoothie Girl
Alongside the planned mini-meals, we suggest eating fresh vegetables and some fruit for live enzymes and bulk fiber.

Flash Fast Early Feedback and Results

Low Hunger

Our first 100 Flash Fasters told us that their highest average hunger level was a 3.4 on a scale of 1 to 10. I consider this one of the most exciting things I’ve learned in my research, because in a country where millions of people have never missed a meal in their lives (unless food poisoning or an intestinal virus was involved), most people can tolerate a 3.4 hunger level (where 10 is “extremely hungry”), but few will power through a fast where their hunger is rated 7 or higher.

Weight Loss: Water and Inflammation

Another exciting outcome, tracking our first 100 Flash Fasters, is that their average weight loss was 4 pounds in 3 days. Some will say, “That has to be part water loss!”

And while we are sure this is true, our beta testers were encouraged to drink lots of water. Another fascinating statistic from this group explains what that “water loss” actually is: 100% of our first group reported noticeably decreased inflammation. If I can suggest an image to help you visualize, inflammation is angry, red, injured cells that hold onto fluids. Therefore, the healing of inflammation causes billions of cells to each release tiny amounts of dirty fluids trapped in these areas of systemic inflammation. “Water loss,” then, is at least as positive and helpful as fat loss.

Photo of woman stirring GreenSmoothieGirl chocolate plant protein powder into glass of water from "Modified Fasting 101: The Ultimate Beginner’s Guide" by Green Smoothie Girl
Losing weight during a modified fast is not only from water loss.

Cognitive, Mood, Digestion, and Pain Improvements

In addition to the 100% of subjects reporting decreased inflammation, the other top results of our early Flash Fasters include weight loss for 100% of them and the vast majority experiencing clearer thinking, stabilized mood, better sleep, better digestion, and decreased pain.

While our own gathering of information about Flash Fasters’ results is currently in its infancy, I will revisit this blog post and continue to update it with results and more information. We're keeping an ear to the ground and taking note of everything Flash Fasters tell us about their experiences.

We ship each first-time Flash Faster a free copy of my 70-page mini-book called How to Get the Health Benefits of Fasting—Without Going Hungry. The book is a “Cliff’s Notes” of the published research on modified fasting.

Photo of Green Smoothie Girl Modified Flash Kit and Booklet from "Modified Fasting 101: The Ultimate Beginner’s Guide" by Green Smoothie Girl
Each Flash Fast kit comes with my Modified Fasting book, but you can download it for free as well!

Almost 70 percent of our first 100 Flash Fasters reported reading the mini-book, and this comment by Peggy G. is typical of those who took an hour to read it:

“Reading the book, I became very committed to the idea that fasting is the best health preventative I’ll ever do. Now I’m excited to do it once a month!”

My Experience Doing the Flash Fast Weekly for a Month

During the month before we launched the Flash Fast to our audience, and in the month following, I personally Flash Fasted Monday to Wednesday every week.

I wanted to see if doing the fast that often would cause me to get lightheaded. I wanted to test whether I could play competitive tennis matches while fasting, just like I do, year-round, when I’m not fasting. I wanted to know if I'd become ravenously hungry and emotionally deprived and end up eating everything in sight after the 3 days ended.

inline flash fast easy green smoothie girl

Week after week, I became more excited as I played tennis matches on Day 2 and even Day 3 of my Flash Fasts, playing well and with plenty of energy. (I did make sure to time one of my mini-meals for right before I walked on the court.)

I never once experienced lightheadedness, and I was even able to work fulltime, managing my company, without the brain fogs, low energy, kidney pain, or adrenaline surges that plagued me when I did water fasts at the ashram.

I did not overeat, and wasn’t even tempted to overeat, on the days following Flash Fasting. I am pleased to report I experienced none of those “dark sides” of the water-fasting experience, while doing the Flash Fast 8 times now!

“Refeeding:” Eating After Fasting

For the sake of the “re-feeding” process after you complete a fast or modified fast, it's important to eat an organic, whole-food, plant-based diet for at least an equivalent number of days as the fast.

After all, in the breakdown of cancerous growths, bacterial and viral colonies, yeast, and fungus and mold, you’ll have those byproducts working their way out, through various organs of elimination, like the colon, kidneys, and liver. These processes do not end abruptly as you finish fasting; there's a lot of old, broken down matter still in transit.

Flat vector illustration of a plate with Autophagy lettering on it with a fork and a knife from "Why I Developed The Flash Fast: Modified Fasting Made Easy And Fun" by Green Smoothie Girl
Fasting promotes autophagy (natural cell death) of old cells. Rebuilding new ones requires healthy ingredients.

When old, defective, or mutated cell parts are metabolized by the host cell in the process of autophagy, these parts then need to be rebuilt! You want quality food after the fast to support a healthy rebuild. After all, “you are what you eat!”

Longo explains autophagy with the metaphor of a wood-burning train. If the train can’t get to the next station with the fuel it has, you may need to go to the cabin, rip out an old wooden chair or two, and throw it into the fire. But then, when you do arrive at the station, you’ll need to rebuild the missing chairs you tore out.

You’ll definitely want to have quality materials available for your body's rebuilding process. For this reason, it’s a bad idea, after a 3-day modified fast such as the Flash Fast, to celebrate by drinking a bottle of wine or snacking on Cheetos and chocolate donuts, washed down with a Diet Pepsi.

You want the days following your fast to be comprised of 95% or more greens, vegetables, fruits, legumes, whole grains, nuts, and seeds.

[Get more information on refeeding in my free ebook on modified fasting.]

Read next: What Can You Drink During Modified Fasting? Tips, Recipes, and Best Practices

Photograph of Robyn Openshaw, founder of Green Smoothie GirlRobyn Openshaw, MSW, is the bestselling author of The Green Smoothies Diet, 12 Steps to Whole Foods, and 2017’s #1 Amazon Bestseller and USA Today Bestseller, Vibe. Learn more about how to make the journey painless, from the nutrient-scarce Standard American Diet, to a whole-foods diet, in her free video masterclass 12 Steps to Whole Foods.

Photo of open Flash Fast kit box showing individual mini meals and fasting booklet with post's title text overlay from "Why I developed the Flash Fast" by Green Smoothie Girl


  1. Anton SD, Moehl K, Donahoo WT, et al. Flipping the Metabolic Switch: Understanding and Applying the Health Benefits of Fasting. Obesity (Silver Spring). 2018;26(2):254–268. doi:10.1002/oby.22065
  2. Cheng, Chia-Wei et al. Fasting-Mimicking Diet Promotes Ngn3-Driven β-Cell Regeneration to Reverse Diabetes. Cell. 02/2017.
  3. Levine B, Klionsky DJ. Autophagy wins the 2016 Nobel Prize in Physiology or Medicine: Breakthroughs in baker's yeast fuel advances in biomedical research. Proc Natl Acad Sci U S A. 2017;114(2):201–205. doi:10.1073/pnas.1619876114
  4. Longo, V. D., & Mattson, M. P. (2014). Fasting: molecular mechanisms and clinical applications. Cell metabolism, 19(2), 181–192. doi:10.1016/j.cmet.2013.12.008.
  5. Brandhorst S, Longo VD. Fasting and caloric restriction in cancer prevention and treatment. Recent Results Cancer Res. 2016;207:241-266. doi:10.1007/978-3-319-42118-6_12
  6. University of Wisconsin-Madison. "Discovery opens new opportunities to slow or reverse multiple sclerosis." ScienceDaily. 27 November 2018.
  7. Heilbronn L.K., de J.L., Frisard M.I., DeLany J.P., Larson-Meyer D.E., Rood J., Nguyen T., Martin C.K., Volaufova J., Most M.M., et al. Effect of 6-month calorie restriction on biomarkers of longevity, metabolic adaptation, and oxidative stress in overweight individuals: A randomized controlled trial. JAMA. 2006;295:1539–1548. doi: 10.1001/jama.295.13.1539.
  8. Boya P., Codogno P., Rodriguez-Muela N. (2018). Autophagy in stem cells: repair, remodelling and metabolic reprogramming. Development. 145, pii: dev146506. 10.1242/dev.146506
  9. Wei, Min et al. Fasting-Mimicking Diet and Markers/Risk Factors for Aging, Diabetes, Cancer, and Cardiovascular Disease. Science Translational Medicine. 02/2017.
  10. Fung, Jason Dr. How to Fix Your Broken Metabolism by Doing the Exact Opposite. Intensive Dietary Management.

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Posted in: Detox, Fasting, High-Vibe Living, Lifestyle, Mothers Without Borders, Natural Products, Preventive Care

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