From fasting through chemo to a 24-hour reset to prolonged healing fasts — discover the fast that matches your goals, guided by an Oncologist, Dr. Katie Deming, MD.
Water fasting is the voluntary absence of food — a natural, ancient practice that lets the body rest, clear out, and heal in its own intelligent way. When you stop digesting, the energy your body spends on food goes toward repair instead.
There isn't one “right” fast. The best fast for you depends on your goal — whether that's a gentle metabolic reset, support through chemotherapy, or deep healing of chronic illness. This page helps you find yours, and shows why so many choose to fast with Dr. Katie.
Answer a few quick questions about your goals and where you are in your health journey. We'll point you toward the fast that fits — and Dr. Katie will share guidance to help you start safely.
Take the Free Quiz →The water fasting spectrum runs from a single day to prolonged fasting. Here's what each one does, who it's best for, and what to expect.
The easiest place to begin. A weekly 24-hour fast improves insulin sensitivity and lowers inflammation — with no disruption to your day.
A short fast timed around chemotherapy or immunotherapy infusions. Through differential stress resistance, healthy cells shift into a protective mode that cancer cells can't — leaving tumor cells sensitive to treatment while shielding the rest of you.
A metabolic reset. Dr. Katie does a 3-day fast every month, and if you join Dr. Katie's Fasting Circle™, you have the opportunity to do a 5-day fast every quarter.
Past day seven, the body begins preferentially breaking down diseased and damaged tissue for fuel — the point where deep healing begins. Detoxification peaks between days four and seven, and the nervous system settles into a profound calm.
The most powerful fast in the spectrum — and the one Dr. Katie says she would choose for herself if facing a cancer diagnosis. The body heals in reverse: old injuries and conditions surface and resolve, the immune system and microbiome fully reset, and many describe it as the most transformative experience of their lives.
Every additional day unlocks a deeper stage of healing. Here's the journey.
Blood glucose and insulin fall, glycogen stores deplete, fat-burning starts, and growth hormone rises to protect muscle.
The body shifts to ketones for fuel. Autophagy switches on, IGF-1 and mTOR drop, and mental clarity sharpens.
Therapeutic ketosis deepens, stem-cell activity rises, detox peaks, inflammatory markers fall, and the nervous system calms.
The body preferentially breaks down diseased tissue, repair intensifies, and deep emotional and spiritual healing unfolds.
Fast in a guided group with daily coaching, or apply for a supervised prolonged fast built around your goals.
Dr. Katie Deming is a Duke-trained radiation oncologist who practiced conventional medicine from 2006 to 2022 and treated more than 5,000 patients, specializing in breast and gynecologic cancers.
After two decades inside the system — and a profound personal experience that changed everything — she left Western medicine to explore what truly makes people well. That search led her to water fasting. Her very first fasting client, a 58-year-old woman with stage IV breast cancer, completed a 17-day fast alongside conventional care; three months later, her brain scan was clear. That moment opened Dr. Katie's eyes to fasting as one of nature's most powerful healing tools.
Today she guides people through the full spectrum of water fasting — pairing rigorous medical knowledge with deep care for the emotional, mental, and spiritual sides of healing — through her practice and her podcast, Born to Heal.
Water fasting has a remarkable safety record. The most important part of any longer fast is proper, supervised refeeding, which is why prolonged fasts should always be done with expert guidance.
Fasting is not recommended for those who are:
Most people, however, can fast safely with the right support. The quiz and a consult help determine what's appropriate for you.
Take the two-minute quiz to find the fast that fits your goals — and start your healing journey with Dr. Katie.
Take the Free Quiz →