Occasionally, a guest arrives at the Prama Institute and Wellness Center, convinced that “real” fasting means water only. Nothing but water, for a week or more, and the deeper the deprivation, the deeper the healing. It is an appealing story. The research, however, points to a gentler way of fasting—one we have practiced for years.
The largest fasting study ever conducted
In 2019, a team led by Françoise Wilhelmi de Toledo published results from 1,422 people who completed fasting periods of 4 to 21 days at the Buchinger Wilhelmi clinic in Germany. Participants did not drink water alone. They took in roughly 200–250 calories a day — water, a little fruit juice, a cup of vegetable broth — alongside movement, rest, and a structured lifestyle program.
The results were remarkable. Weight, waist circumference, and blood pressure all dropped significantly. Blood lipids and glucose regulation improved. Ketone bodies rose, and blood glucose settled into the low normal range, confirming the metabolic switch from sugar-burning to fat-burning. Physical and emotional well-being increased, and 93.2% of participants reported no feeling of hunger at all. Among the 404 people who arrived with existing health complaints, 84.4% reported improvement. Adverse effects, what we at Prama call “healing symptoms,” appeared in fewer than 1% of participants.
The contrast with water-only fasting
Water-only fasting produces real benefits too — weight loss, reductions in blood pressure, improved insulin, and more. Supervised water fasting has been studied as a treatment for stage 1 hypertension with encouraging results at True North Health Foundation in California.
But the cost side of the ledger looks different. As Dr. Michael Greger has noted, the modified-juice fasting cohort of more than a thousand people reported very few side effects, while water-only fasting data from a study involving roughly half as many people documented nearly 6,000 adverse events. A separate chart review of medically supervised water-only fasting found thousands of adverse events, most mild, but with more severe events recorded in 212 visits.
I have personally encountered people who have fainted during a water fast; one person even fell down the stairs. As Dr. Joel Fuhrman suggests, water fasting requires 24-hour medical supervision to be done responsibly. As the study cited above shows, a small amount of juice and broth changes the entire risk profile—and, importantly, the experience. Some more juice and broth, about 500-600 calories a day, makes the experience and the health benefits even more profound.
What we actually do at Prama
Here is where we differ from Buchinger, and deliberately so: our guests take in roughly 500–600 calories of micronutrient juice per day—two fresh juice meals and one serving of warm vegetable broth. That is more than double the Buchinger intake, and it is a choice, not a compromise.
Ketosis and autophagy still happen. The metabolic switch does not require starvation. At this intake level, our guests still move into fat-burning and ketone production, rest the digestive system, and get the cellular cleanup called autophagy that draws people to fasting in the first place.
We also ask people to practice. A Prama fast is not bed rest. Guests practice yoga and several rounds of meditation each day. They also hike and sweat in the sauna. These kinds of practices take energy. The broth in the late afternoon — warm and mineral-rich — is what makes an evening meditation sitting feel peaceful rather than tired and shaky. It also helps maintain electrolytes, one of the real vulnerabilities of water-only fasting.
The refeeding matters as much as the fast. We plan the refeeding process over two to six days, depending on how long they fasted, how far along they are, and each person’s health status. The fast is not the whole intervention; the return is where the new eating pattern is set. Studies show that many water fasters fail during this refeeding process. They eat too much too quickly and thus do more harm than good. The various documentaries on fasting don’t help, as none of them discuss how to properly refeed or how to cleanse the colon during the fast with enemas and/or herbs.
Fasting as practice, not as punishment
An old ascetic tradition in yoga and Western natural hygiene alike equates severity with virtue. However, the largest study we have does not support these habits. Prama’s gentle, supervised, nutrient-supported fasting delivered the physiological benefits with almost no harm and, strikingly, almost no hunger.
At Prama, we see fasting as one part of a holistic method — fasting, plant-based nutrition, yoga, meditation, and plant-based nutritional education together. The juice and the broth are not a dilution of the fast. They enhance the benefits of the fast.
If you want to go deeper into this lifestyle, bring your appetite for whole health to Prama. We will manage the juice, the broth, and the yoga.
Sources
Wilhelmi de Toledo F, Grundler F, Bergouignan A, Drinda S, Michalsen A. “Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects.” PLOS ONE, 2019. https://journals.plos.org/plosone/article?id=10.l1371/journal.pone.0209353
“Efficacy and safety of prolonged water fasting.” PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC11494232/
“Is fasting safe? A chart review of adverse events during medically supervised water-only fasting.” PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC5819235/
“Prolonged Water-only Fasting is a Safe and Feasible Treatment Option for Managing Stage 1 Hypertension.” TrueNorth Health Foundation. https://www.truenorthhealthfoundation.org/original-research/prolonged-water-only-fasting-safe-and-feasible-treatment-option-managing-stage-1
Greger M. “The Largest Study on Fasting in the World.” NutritionFacts.org. https://nutritionfacts.org/blog/the-largest-study-on-fasting-in-the-world/
Ramesh Bjonnes
Ramesh Bjonnes has been teaching and writing about yoga philosophy and history for the past 25 years. He is the co-founder of the Prama Institute, a yoga retreat center in the Blue Ridge Mountains of North Carolina, USA, where he is director of the Prama Wellness Center. He is the author of three books on yoga and Tantra, including A Brief History of Yoga. His forthcoming book is titled The Lost Teachings of Tantra. Websites: www.prama.org www.rameshbjonnes.org
Books
Sacred Body, Sacred Spirit
Only – $12.40
Other Blogs Posts
CCF Tea: Ayurvedic Tea for Gut Health
Occasionally, a guest arrives at the Prama Institute and Wellness Center, convinced that “real” fasting means water only. Nothing but water, for a week or more, and the deeper the deprivation, the deeper the healing. It is an appealing story. The research, however, points to a gentler way of fasting—one we have practiced for years.
Food and Fasting for Healing and Health
If the body naturally detoxes every day, even while we sleep, why is it still important to detox with a juice cleanse or alkaline superfoods? Because the food we eat is not always healthy or alkaline; it may contain too much acid-producing processed flour, sugar, animal fat, and dairy. When we overeat, too many toxins are left in the body. Stress is another reason; too much work and too little sleep will create imbalances in the body’s digestive ecology.
