72-Hour Water Fast: Autophagy, Weight Loss & Mental Clarity

Inspired by numerous podcasts, articles, and the influence of Dr. Sten, the speaker committed to a 72‑hour water fast. The stated goals were to trigger autophagy, achieve cellular cleaning, gain mental clarity, and explore any longevity benefits. The fast was scheduled from Monday at 4:30 p.m. to Thursday at the same time.

Pre‑Fast Meal and Preparation

The last meal before the fast consisted of a large steak and eggs, deliberately high in fat and protein to maximize satiety and limit carbohydrate withdrawal. The speaker anticipated the upcoming carb deficit and prepared flavored carbonated water, electrolytes, decaf coffee, and herbal tea for the fasting period.

The First 24 Hours: Glycogen Depletion

During the initial day, the speaker, already accustomed to intermittent fasting, found the hours relatively easy. Morning weight was 194 lb, already down 4.9 lb from the previous night. Ketone test strips were negative, indicating the body was still expecting food. The strategy to combat hunger was to stay busy—working, playing with the cat Boba, and assembling a puzzle—so that “if I stay busy, I forget that I’m starving.” This period corresponded to Phase 1, the glycogen depletion stage, where stored carbohydrates are used for energy. A trip to the grocery store was described as a “dangerous game” while fasting.

24–48 Hours: The Dip and Early Ketosis

Around the 26‑hour mark, hunger pangs intensified, accompanied by irritability and a “downward spiral” of mood. The speaker questioned the ability to continue and noted food’s central role in daily life. By 40 hours, weight had dropped to 190.5 lb and the body entered Phase 2, the ketosis phase, where fat becomes the primary fuel and autophagy begins. Sleep quality improved, senses felt heightened, and a sense of peace emerged. Hunger subsided to 2–3 out of 10, skin appeared to glow, and a ketone strip showed a faint pink line indicating trace ketones.

40–53 Hours: Ketosis, Autophagy, and Mental Clarity

At roughly 43 hours, a heavy leg workout was performed. Despite the catabolic feeling of muscles “screaming for protein,” the speaker experienced unexpected focus, aggression, and strength, attributing it to a possible “couple hundred percent” increase in human growth hormone. Post‑workout, the physique update was positive, though hunger spikes aligned with normal eating times. The speaker described moments of “ascension” and “powers,” comparing the experience to previous habits of giving in to food. Mental clarity persisted, even as a head throbbing and a desire to watch cooking reels made concentration difficult. By 49 hours, the speaker faced a difficult period, making a dinner for the wife as exposure therapy, and noted the body relying on fat oxidation and ketone production—a classic “keto flu” phase.

53–72 Hours: Full Ketosis, Physical Shifts, and Emotional Landscape

From 53 hours onward, the speaker felt detached, moving in “slow motion” with laser‑like focus and heightened senses. Hunger rose to 6/10, described as the body “eating itself.” At 64 hours, weight was 188.7 lb, a total loss of over 10 lb, and a ketone strip turned dark pink, confirming moderate ketosis. Phase 3, full ketosis, coincided with peak autophagy. Joints and tendons felt about 90 % better, and there was no soreness after the earlier leg day despite the lack of fuel. The speaker chose not to exert further at the gym, opting instead for a brief sauna session that felt like a “turkey in the oven,” prompting concern about electrolyte loss, and a deep massage where muscles were too relaxed to tense. With less than two hours left, the speaker expressed disbelief at having completed 71 hours.

Breaking the Fast: Gentle Refeeding

The refeeding plan emphasized a gentle reintroduction of food to avoid shocking the system. Grocery shopping yielded beef bone broth, eggs, and roasted potatoes—chosen for their recovery properties, including choline and B vitamins in eggs. The Macroactor app was used to track intake. The first post‑fast meal consisted of bone broth, three eggs, and roasted potatoes. Chewing felt like a rediscovered skill, and the speaker felt proud and emotional at the completion of the 72‑hour fast.

Post‑Fast Reflections and Lessons

Total weight loss was 10.2 lb, primarily water weight. The speaker noted reduced bloating, smoother skin, and a more even complexion. Key learnings included recognizing how food‑focused life can be, the importance of slowing down to appreciate simple beauties, and the humbling perspective that fasting provides. The experience was described as a reminder that “life doesn’t need to revolve around food” and that “life is beautiful, taking things for granted, need to slow down.” The speaker recommends trying fasting at least once and wonders whether fasting could be “the key to peak existence or eternal happiness.”